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

Annotations already declare readOnlyHint and idempotentHint, so the description adds value beyond safety. It discloses behavioral traits such as nearest-first ordering, inclusion of the stop/station id, and the distinction between London live data and timetable-based data elsewhere. This is relevant for interpreting results.

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 two sentences long, front-loaded with the core purpose, and every word adds value: nearest-first, id inclusion, and data source. There is no redundant or filler content.

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 moderate complexity, the description covers essential context: what it returns (stops/stations and ids), ordering, and data source. There is no output schema, but the description is informative enough for basic invocation. Minor gaps exist around the full return structure, but overall adequate.

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 already covers 100% of parameters with descriptions ('Latitude', 'Longitude', and radius with default/max). The description does not add significant semantic meaning to the parameters beyond what the schema provides, so the baseline of 3 is appropriate.

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 finds 'bus stops and stations near a point' and adds specific scope details: nearest-first ordering, the id each stop is called by, and data sources (London TfL vs published timetables). This distinguishes it from sibling tools like transit_arrivals or places_nearby, which focus on different resources.

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 provides clear context on when the tool applies: for finding transit stops near a point, with geographic coverage specified. It does not explicitly name alternatives or exclusions, but the context is sufficient for an agent to decide this is the right tool for nearby transit searches.

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