MBTA MCP Server

mbta_list_all_routes

List all MBTA transit routes. Filter results using optional fuzzy search by route name.

List all MBTA routes with optional fuzzy filtering. Returns all routes without specific filters, with client-side fuzzy search.

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "mbta_list_all_routes"
  }
}

Name	Required	Description	Default
`query`	No	Optional fuzzy search query to filter routes by name
`max_results`	No	Maximum number of results to return (default: 50)

Changes observed during successful MCP inspections.

A3.7/5.0

Behavior2/5

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

No annotations; description only mentions client-side fuzzy search, leaving out auth needs, rate limits, or response traits.

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?

Two sentences, no fluff, front-loaded with core action.

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

Completeness3/5

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

No output schema; description doesn't specify return format or pagination. Adequate for a simple list but gaps remain.

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

Parameters4/5

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

Schema covers 100% of params; description adds context that query is fuzzy and client-side, and max_results limits output, going beyond schema.

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?

Verb 'List' + resource 'all MBTA routes' is specific and distinguishes from siblings like mbta_get_routes. Optional fuzzy filtering adds clarity.

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

Usage Guidelines3/5

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

Implies use for fetching all routes or filtered results, but no explicit when-to-use vs alternatives (e.g., mbta_get_routes) or conditions.

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