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

Annotations already declare read-only, idempotent, open-world, and non-destructive behavior. The description adds valuable context beyond those: the data source (community HAFAS wrapper v6.bvg.transport.rest), no-auth requirement, a concrete rate limit (100 req/min), and the walking-distance sort. Nothing contradicts the annotations.

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 tight sentences. The first front-loads the action, scope, and ordering; the second efficiently adds the data source, authentication, rate limit, and a representative use case. There is no filler or redundancy.

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 read-only point-to-stops query, the description provides the critical non-schema context: geographic scope (Berlin/Brandenburg), data provenance, auth status, rate limits, and sorting behavior. Combined with the full parameter schema and output schema, nothing an agent needs to invoke it correctly is missing.

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 every parameter already carries its own description, so the baseline is 3. The description reinforces latitude/longitude and walking-distance semantics, but it does not add new details about results or max_distance_meters beyond the schema. This is appropriate since the schema is already self-sufficient.

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 opens with a specific verb and resource: 'Find public transit stops/stations near a latitude/longitude coordinate in Berlin/Brandenburg'. It adds a distinctive sorting detail ('sorted by walking distance') and implicitly differentiates itself from the sibling transit tools by focusing on stop discovery rather than departures, journey planning, or location search.

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?

It gives a concrete, scoped use case: 'Useful for "what transit is near this address" queries'. This is clear context for when to invoke the tool, but it does not explicitly mention alternatives or state when not to use it, such as pointing to transport-rest.transit.search_locations for name-based lookups.

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