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

Annotations already establish read-only, idempotent, non-destructive, open-world behavior. The description adds useful context beyond that: MTS-K real-time data, Germany-only scope, EUR-per-liter pricing, and the concrete set of returned station attributes.

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 front-loaded with the core purpose, then efficiently lists returned fields and scope. The example call is compact and reinforces the required parameter format without excessive verbosity.

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 detail lookup with no output schema, the description adequately explains what is returned, the data source, region constraint, and how to obtain the required id. Nothing critical for correct invocation appears 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 description coverage is 100%, so both parameters are already documented in the input schema. The description repeats that station_id is a UUID from tankerkoenig_stations_nearby but adds no syntax, format, or constraint beyond 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 this returns full detail for one German gas station identified by Tankerkoenig station id, and explicitly lists the returned fields. It also distinguishes itself from tankerkoenig_stations_nearby by requiring a UUID sourced from that tool.

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 clear usage context: use a station UUID from tankerkoenig_stations_nearby, and the tool is Germany-only. It does not explicitly state when to use tankerkoenig_prices instead or add exclusions, so it falls short of full alternative routing.

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