ts-mcp-server

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Prepare Call Hierarchy

prepareCallHierarchy

Read-only

Retrieve call hierarchy items (function/method name, kind, file location, and spans) at a specific position in a TypeScript or JavaScript file to analyze function calls.

Instructions

Returns the call hierarchy item(s) at a position — the entry point for call hierarchy queries. Returns the function/method name, kind, file location, and spans.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "file": "<file>",
      "line": "<line>",
      "offset": "<offset>"
    },
    "name": "prepareCallHierarchy"
  }
}

Input Schema

Name	Required	Description
`file`	Yes	File path (absolute or relative to cwd)
`line`	Yes	1-based line number
`offset`	Yes	1-based character offset on the line

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.1.1Jul 12, 2026

TDQS

A4.2/5.0

Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description aligns with the readOnlyHint annotation by not implying any side effects. It adds value by detailing the return fields (name, kind, file location, spans), which goes beyond the structured annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise, consisting of two sentences that front-load the primary purpose and then list the return information. No extraneous text.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's simplicity, read-only nature, full schema coverage, and lack of output schema, the description adequately covers behavior and return information. It is complete enough for an agent to understand usage.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema already covers all three parameters with descriptions (file path, line, offset). The tool description does not add additional semantics beyond what the schema provides, so the baseline score of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the verb ('Returns') and resource ('call hierarchy item(s) at a position'), and it distinguishes itself from sibling tools by calling itself 'the entry point for call hierarchy queries', which implies a specific role in the workflow.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description indicates it is the entry point for call hierarchy queries, providing context for when to use this tool before other call hierarchy commands. However, it does not explicitly state when not to use it or offer alternatives.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.