Skip to main content
Glama
Sign In
ts-mcp-server

ts-mcp-server

by AndyLiner13
OverviewSchemaSourceRelated ServersDiscussionsAdmin
TypeScript
Local

Extract Constant

extractConstant
Destructive

Extract a selected expression into a named constant with TypeScript type inference. Preview changes before applying, and rename the constant afterwards.

Instructions

Extract the selected expression into a named constant. TypeScript infers the type. The response includes renameFilename/renameLocation so you can follow up with rename_symbol to give the constant a meaningful name.

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>",
      "startLine": "<startLine>",
      "startOffset": "<startOffset>",
      "endLine": "<endLine>",
      "endOffset": "<endOffset>",
      "preview": "<preview>"
    },
    "name": "extractConstant"
  }
}

Input Schema

NameRequiredDescriptionDefault
fileYesFile path (absolute or relative to cwd)
endLineYes1-based end line
previewYesIf true, only preview changes
endOffsetYes1-based end character offset
startLineYes1-based start line
startOffsetYes1-based start character offset

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv1.1.1

TDQS

A4/5.0
Behavior3/5

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

The description adds some behavioral context beyond annotations: it mentions TypeScript infers the type and that the response includes rename info. However, the destructiveHint annotation already indicates modification, and the description does not elaborate on the effect on the file or other side effects.

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 two sentences, concise and to the point, with no unnecessary words. It efficiently communicates the tool's purpose and a key follow-up detail.

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?

The description covers the essential purpose and a crucial output detail (rename info) for follow-up. Since there is no output schema, the description compensates reasonably well. However, it could mention where the constant is placed or any default naming behavior.

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?

Schema description coverage is 100% (all parameters have descriptions). The description does not add additional meaning to the parameters beyond what the schema already provides, so a 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 action ('Extract') and the resource ('selected expression into a named constant'). It distinguishes from sibling tools like extractFunction and extractType that extract into different constructs.

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 explains when to use this tool (to extract an expression into a constant) and suggests a follow-up action (rename_symbol). While it does not explicitly exclude other tools, the clear purpose implicitly differentiates it from siblings.

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

Deploy Server

Other Tools