Get one route in full

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

Annotations already declare readOnlyHint=true and idempotentHint=true, but the description adds valuable context: unknown id returns close-match suggestions instead of failing. 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?

Two sentences: first sentence describes the tool's function and output; second sentence provides usage guidance. Every sentence is essential, no fluff, and information is front-loaded.

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?

Despite lacking an output schema, the description lists the return fields, which is sufficient. It also covers behavior on unknown id. Given the tool's simplicity (single parameter, read-only, idempotent) and comprehensive annotations, the description is complete.

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% (1 parameter), so baseline is 3. The description provides additional context for the 'id' parameter beyond the schema, including format (kebab-case), example, and source (search_routes, famous_routes, routes_in_country). This adds meaning.

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 'Full record for one atlas route by exact id' and enumerates the specific fields (distance, fastest time, etc.), distinguishing it from sibling tools like search_routes which would be used for name-based lookup.

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?

Explicitly guides when to use this tool vs. alternatives: 'Use search_routes first when you only have a name or city.' Also explains behavior for unknown id (returns up to 5 close-match suggestions), which helps the agent decide how to handle edge cases.

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