get_route_by_stop

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

Annotations cover key behavioral traits (read-only, non-destructive, idempotent, closed-world), so the bar is lower. The description adds value by specifying the filtering logic ('pass through a specific stop'), which isn't captured in annotations. It doesn't contradict annotations and provides useful operational context, though it could mention more about output format or limitations.

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?

The description is a single, clear sentence that front-loads the core functionality without unnecessary words. It efficiently conveys the tool's purpose and filtering logic, making it easy to parse and understand quickly.

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?

Given the tool's low complexity (1 parameter), rich annotations, and presence of an output schema, the description is reasonably complete. It covers the main purpose and filtering aspect, and the output schema likely handles return values. However, it could be more comprehensive by mentioning potential edge cases or linking to sibling tools for better context.

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?

The input schema has 1 parameter with 0% description coverage, but the description compensates by clarifying that 'stop_name' is used to find routes passing through it. However, it doesn't add details like format examples or constraints beyond the basic meaning. With schema coverage low, the description does some work but not fully, aligning with the baseline for minimal param info.

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 tool's purpose with a specific verb ('Find') and resource ('bus routes'), and specifies the condition ('that pass through a specific stop'). It distinguishes from sibling tools like 'get_bus_routes' by focusing on routes filtered by stop. However, it doesn't explicitly differentiate from 'find_bus_stop', which might be a related but distinct operation.

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 when needing routes for a particular stop, but provides no explicit guidance on when to use this tool versus alternatives like 'get_bus_routes' (which might list all routes) or 'find_bus_stop' (which might locate stops). It lacks clear exclusions or prerequisites, leaving usage context somewhat inferred rather than stated.

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