Stations near coordinates

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

Annotations already cover readOnlyHint, openWorldHint, and idempotentHint, so the safety profile is established. The description adds that the returned bahn.de id is usable in every other tool, which is useful context, but it does not disclose behavior like sorting, pagination, or filter defaults. No contradiction with 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?

A single sentence with no redundancy: the core purpose is front-loaded, and the chaining detail about the returned id is valuable and compact. Every word earns its place.

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 moderately simple tool with 5 parameters and an output schema, the description is adequate but leaves gaps around optional parameters like radius_m, max_results, and rail_only. The output schema covers return fields, but the description doesn't explain how these optional parameters shape results.

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 description coverage is only 20%, yet the description only explains that latitude/longitude form a 'GPS position'. It does not add meaning for radius_m (units, default), max_results (cap), or rail_only (beyond the schema's existing one-line description). The description fails to compensate for the schema's low coverage.

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 states a precise verb and resource: 'Stations and stops around a GPS position — 'stations near me''. This clearly differentiates it from sibling db_search_station (name-based lookup) and explains the key output fields including the chaining id.

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 phrase 'around a GPS position' implicitly tells an agent when to use this tool, but it never explicitly names alternatives or states when not to use it. The cross-tool id note guides downstream usage, not tool selection.

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