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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds meaningful behavioral detail beyond annotations: reconstructions are returned side by side rather than merged, and each variant includes ordered stops, hypotheses, confidence rubrics, and sources. 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 with no filler. The core action is front-loaded, and the comparison-oriented behavior is stated efficiently. Every sentence 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?

Given the small parameter count, rich annotations, and presence of an output schema, the description covers what an agent needs to know to call this tool correctly. It explains the route-fetching purpose and the side-by-side reconstruction behavior without unnecessary detail.

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 the schema already documents both slug and locale. The description adds context that slug selects a route and that variants are compared, but it does not add meaning beyond the schema's parameter docs. Baseline 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 states a specific verb and resource ('Get one route by slug') and lists the content of the response, clearly distinguishing this from sibling tools like get_homeric_episode or get_homeric_place. It also contrasts with listing tools by focusing on a single route.

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 gives clear usage context: use this to compare rival reconstructions of a voyage, with reconstructions returned side by side rather than merged. It does not explicitly name alternatives like list_homeric_routes, but the guidance is strong enough for an agent to select this tool appropriately.

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