diff --git a/src/cli/call-argument-expression.ts b/src/cli/call-argument-expression.ts
new file mode 100644
index 0000000..b4a914f
--- /dev/null
+++ b/src/cli/call-argument-expression.ts
@@ -0,0 +1,61 @@
+import { parseCallExpressionFragment } from './call-expression-parser.js';
+import { CliUsageError } from './errors.js';
+import { splitHttpToolSelector } from './http-utils.js';
+
+type ParsedCallExpression = NonNullable<ReturnType<typeof parseCallExpressionFragment>>;
+
+export function parseLeadingCallExpression(rawToken: string): ParsedCallExpression | null {
+  try {
+    return extractHttpCallExpression(rawToken) ?? parseCallExpressionFragment(rawToken);
+  } catch (error) {
+    throw buildCallExpressionUsageError(error);
+  }
+}
+
+function extractHttpCallExpression(raw: string): ParsedCallExpression | null {
+  const trimmed = raw.trim();
+  const openParen = trimmed.indexOf('(');
+  const prefix = openParen === -1 ? trimmed : trimmed.slice(0, openParen);
+  const split = splitHttpToolSelector(prefix);
+  if (!split) {
+    return null;
+  }
+  if (openParen === -1) {
+    return { server: split.baseUrl, tool: split.tool, args: {} };
+  }
+  if (!trimmed.endsWith(')')) {
+    throw new Error('Function-call syntax requires a closing ) character.');
+  }
+  const argsPortion = trimmed.slice(openParen);
+  const parsed = parseCallExpressionFragment(`${split.tool}${argsPortion}`);
+  if (!parsed) {
+    return { server: split.baseUrl, tool: split.tool, args: {} };
+  }
+  return {
+    server: split.baseUrl,
+    tool: split.tool,
+    args: parsed.args,
+    positionalArgs: parsed.positionalArgs ?? [],
+  };
+}
+
+function buildCallExpressionUsageError(error: unknown): CliUsageError {
+  const reason =
+    error instanceof Error
+      ? error.message
+      : typeof error === 'string'
+        ? error
+        : JSON.stringify(error ?? 'Unknown error');
+  const lines = [
+    'Unable to parse function-style call.',
+    `Reason: ${reason}`,
+    '',
+    'Examples:',
+    '  mcporter \'context7.resolve-library-id(libraryName: "react")\'',
+    '  mcporter \'context7.resolve-library-id("react")\'',
+    '  mcporter context7.resolve-library-id libraryName=react',
+    '',
+    'Tip: wrap the entire expression in single quotes so the shell preserves parentheses and commas.',
+  ];
+  return new CliUsageError(lines.join('\n'));
+}
diff --git a/src/cli/call-argument-values.ts b/src/cli/call-argument-values.ts
new file mode 100644
index 0000000..b7f682c
--- /dev/null
+++ b/src/cli/call-argument-values.ts
@@ -0,0 +1,95 @@
+export type CoercionMode = 'default' | 'raw-strings' | 'none';
+
+export interface ParsedKeyValueToken {
+  key: string;
+  rawValue: string;
+  consumed: number;
+}
+
+export function parseKeyValueToken(token: string, nextToken: string | undefined): ParsedKeyValueToken | undefined {
+  const eqIndex = token.indexOf('=');
+  if (eqIndex !== -1) {
+    const key = token.slice(0, eqIndex);
+    const rawValue = token.slice(eqIndex + 1);
+    if (!key) {
+      return undefined;
+    }
+    return { key, rawValue, consumed: 1 };
+  }
+
+  const colonIndex = token.indexOf(':');
+  if (colonIndex !== -1) {
+    const key = token.slice(0, colonIndex);
+    const remainder = token.slice(colonIndex + 1);
+    if (!key) {
+      return undefined;
+    }
+    if (remainder.length > 0) {
+      return { key, rawValue: remainder, consumed: 1 };
+    }
+    if (nextToken !== undefined) {
+      return { key, rawValue: nextToken, consumed: 2 };
+    }
+    warnMissingNamedArgumentValue(key);
+    return { key, rawValue: '', consumed: 1 };
+  }
+
+  return undefined;
+}
+
+export function coerceValue(value: string, coercionMode: CoercionMode = 'default'): unknown {
+  const trimmed = value.trim();
+  if (trimmed === '') {
+    return '';
+  }
+  if (coercionMode === 'none') {
+    return trimmed;
+  }
+  if (trimmed === 'true' || trimmed === 'false') {
+    return trimmed === 'true';
+  }
+  if (trimmed === 'null' || trimmed === 'none') {
+    return null;
+  }
+  if (coercionMode === 'default' && !Number.isNaN(Number(trimmed)) && trimmed === `${Number(trimmed)}`) {
+    return Number(trimmed);
+  }
+  if ((trimmed.startsWith('{') && trimmed.endsWith('}')) || (trimmed.startsWith('[') && trimmed.endsWith(']'))) {
+    try {
+      return JSON.parse(trimmed);
+    } catch {
+      return trimmed;
+    }
+  }
+  return trimmed;
+}
+
+export function shouldPromoteSelectorToCommand(selector: string): boolean {
+  const trimmed = selector.trim();
+  if (!trimmed) {
+    return false;
+  }
+  if (/\s/.test(trimmed)) {
+    return true;
+  }
+  if (/^(?:\.{1,2}\/|~\/|\/)/.test(trimmed)) {
+    return true;
+  }
+  if (/^[A-Za-z]:\\/.test(trimmed) || trimmed.startsWith('\\\\')) {
+    return true;
+  }
+  return false;
+}
+
+function warnMissingNamedArgumentValue(key: string): void {
+  const hint =
+    key === 'command' ? `Example: mcporter call iterm-mcp.write_to_terminal --args '{"command":"echo hi"}'` : undefined;
+  const lines = [
+    `[mcporter] Argument '${key}' was provided without a value.`,
+    `Wrap the entire key/value pair in quotes (e.g., 'command: "echo hi"') or use --args with JSON.`,
+  ];
+  if (hint) {
+    lines.push(hint);
+  }
+  console.warn(lines.join(' '));
+}
diff --git a/src/cli/call-arguments.ts b/src/cli/call-arguments.ts
index b50ab3e..fc50789 100644
--- a/src/cli/call-arguments.ts
+++ b/src/cli/call-arguments.ts
@@ -1,8 +1,12 @@
 import type { EphemeralServerSpec } from './adhoc-server.js';
-import { parseCallExpressionFragment } from './call-expression-parser.js';
+import { parseLeadingCallExpression } from './call-argument-expression.js';
+import {
+  type CoercionMode,
+  coerceValue,
+  parseKeyValueToken,
+  shouldPromoteSelectorToCommand,
+} from './call-argument-values.js';
 import { extractEphemeralServerFlags } from './ephemeral-flags.js';
-import { CliUsageError } from './errors.js';
-import { splitHttpToolSelector } from './http-utils.js';
 import { consumeOutputFormat } from './output-format.js';
 import type { OutputFormat } from './output-utils.js';
 import { consumeTimeoutFlag } from './timeouts.js';
@@ -21,8 +25,6 @@ export interface CallArgsParseResult {
   saveImagesDir?: string;
 }
 
-type CoercionMode = 'default' | 'raw-strings' | 'none';
-
 interface FlagParseState {
   coercionMode: CoercionMode;
 }
@@ -79,19 +81,7 @@ export function parseCallArguments(args: string[]): CallArgsParseResult {
 
   if (positional.length > 0) {
     const rawToken = positional[0] ?? '';
-    let callExpression: ReturnType<typeof parseCallExpressionFragment> | null = null;
-    try {
-      callExpression = extractHttpCallExpression(rawToken);
-    } catch (error) {
-      throw buildCallExpressionUsageError(error);
-    }
-    if (!callExpression) {
-      try {
-        callExpression = parseCallExpressionFragment(rawToken);
-      } catch (error) {
-        throw buildCallExpressionUsageError(error);
-      }
-    }
+    const callExpression = parseLeadingCallExpression(rawToken);
     if (callExpression) {
       positional.shift();
       callExpressionProvidedServer = Boolean(callExpression.server);
@@ -254,145 +244,3 @@ function consumeFlagValue(args: string[], index: number, token: string, missingV
   }
   throw new Error(missingValueMessage ?? `Flag '${token}' requires a value.`);
 }
-
-interface ParsedKeyValueToken {
-  key: string;
-  rawValue: string;
-  consumed: number;
-}
-
-function parseKeyValueToken(token: string, nextToken: string | undefined): ParsedKeyValueToken | undefined {
-  const eqIndex = token.indexOf('=');
-  if (eqIndex !== -1) {
-    const key = token.slice(0, eqIndex);
-    const rawValue = token.slice(eqIndex + 1);
-    if (!key) {
-      return undefined;
-    }
-    return { key, rawValue, consumed: 1 };
-  }
-
-  const colonIndex = token.indexOf(':');
-  if (colonIndex !== -1) {
-    const key = token.slice(0, colonIndex);
-    const remainder = token.slice(colonIndex + 1);
-    if (!key) {
-      return undefined;
-    }
-    if (remainder.length > 0) {
-      return { key, rawValue: remainder, consumed: 1 };
-    }
-    if (nextToken !== undefined) {
-      return { key, rawValue: nextToken, consumed: 2 };
-    }
-    warnMissingNamedArgumentValue(key);
-    return { key, rawValue: '', consumed: 1 };
-  }
-
-  return undefined;
-}
-
-function warnMissingNamedArgumentValue(key: string): void {
-  const hint =
-    key === 'command' ? `Example: mcporter call iterm-mcp.write_to_terminal --args '{"command":"echo hi"}'` : undefined;
-  const lines = [
-    `[mcporter] Argument '${key}' was provided without a value.`,
-    `Wrap the entire key/value pair in quotes (e.g., 'command: "echo hi"') or use --args with JSON.`,
-  ];
-  if (hint) {
-    lines.push(hint);
-  }
-  console.warn(lines.join(' '));
-}
-
-function extractHttpCallExpression(raw: string): ReturnType<typeof parseCallExpressionFragment> | null {
-  const trimmed = raw.trim();
-  const openParen = trimmed.indexOf('(');
-  const prefix = openParen === -1 ? trimmed : trimmed.slice(0, openParen);
-  const split = splitHttpToolSelector(prefix);
-  if (!split) {
-    return null;
-  }
-  if (openParen === -1) {
-    return { server: split.baseUrl, tool: split.tool, args: {} };
-  }
-  if (!trimmed.endsWith(')')) {
-    throw new Error('Function-call syntax requires a closing ) character.');
-  }
-  const argsPortion = trimmed.slice(openParen);
-  const parsed = parseCallExpressionFragment(`${split.tool}${argsPortion}`);
-  if (!parsed) {
-    return { server: split.baseUrl, tool: split.tool, args: {} };
-  }
-  return {
-    server: split.baseUrl,
-    tool: split.tool,
-    args: parsed.args,
-    positionalArgs: parsed.positionalArgs ?? [],
-  };
-}
-
-function coerceValue(value: string, coercionMode: CoercionMode = 'default'): unknown {
-  const trimmed = value.trim();
-  if (trimmed === '') {
-    return '';
-  }
-  if (coercionMode === 'none') {
-    return trimmed;
-  }
-  if (trimmed === 'true' || trimmed === 'false') {
-    return trimmed === 'true';
-  }
-  if (trimmed === 'null' || trimmed === 'none') {
-    return null;
-  }
-  if (coercionMode === 'default' && !Number.isNaN(Number(trimmed)) && trimmed === `${Number(trimmed)}`) {
-    return Number(trimmed);
-  }
-  if ((trimmed.startsWith('{') && trimmed.endsWith('}')) || (trimmed.startsWith('[') && trimmed.endsWith(']'))) {
-    try {
-      return JSON.parse(trimmed);
-    } catch {
-      return trimmed;
-    }
-  }
-  return trimmed;
-}
-
-function buildCallExpressionUsageError(error: unknown): CliUsageError {
-  const reason =
-    error instanceof Error
-      ? error.message
-      : typeof error === 'string'
-        ? error
-        : JSON.stringify(error ?? 'Unknown error');
-  const lines = [
-    'Unable to parse function-style call.',
-    `Reason: ${reason}`,
-    '',
-    'Examples:',
-    '  mcporter \'context7.resolve-library-id(libraryName: "react")\'',
-    '  mcporter \'context7.resolve-library-id("react")\'',
-    '  mcporter context7.resolve-library-id libraryName=react',
-    '',
-    'Tip: wrap the entire expression in single quotes so the shell preserves parentheses and commas.',
-  ];
-  return new CliUsageError(lines.join('\n'));
-}
-
-function shouldPromoteSelectorToCommand(selector: string): boolean {
-  const trimmed = selector.trim();
-  if (!trimmed) {
-    return false;
-  }
-  if (/\s/.test(trimmed)) {
-    return true;
-  }
-  if (/^(?:\.{1,2}\/|~\/|\/)/.test(trimmed)) {
-    return true;
-  }
-  if (/^[A-Za-z]:\\/.test(trimmed) || trimmed.startsWith('\\\\')) {
-    return true;
-  }
-  return false;
-}