mbta_list_all_lines

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

No annotations are provided, so the description carries the full burden. It discloses the client-side fuzzy search behavior and implies a read-only operation, but does not detail data freshness, response size limits, or pagination behavior beyond the max_results parameter.

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

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

Two succinct sentences that front-load the core purpose and immediately follow with the key qualifier (optional fuzzy filtering). No redundant or extraneous information.

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

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

For a simple list tool with two optional parameters and no output schema, the description covers the main functionality and behavior. It could mention the output format or any inherent limits, but is largely complete given the tool's simplicity.

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

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

Schema coverage is 100%, and the description adds value by specifying that filtering is 'client-side' and 'fuzzy' beyond the schema's description of 'Optional fuzzy search query'. The 'max_results' default is already in the schema.

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

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

The description clearly states the action ('List'), the resource ('all MBTA lines'), and the optional feature ('fuzzy filtering'). It distinguishes from sibling tools that list routes or alerts by specifying 'lines'.

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

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

The description implies usage for retrieving lines with optional filtering, but does not explicitly state when to prefer this tool over alternatives like 'mbta_get_routes' or 'mbta_list_all_routes'. No 'when not to use' guidance is provided.

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