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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds a preview of returned content (summary, stations with nights and reasons, best months, highlights, link), which helps relevance judgment, but it says nothing about the language parameter's effect, invalid-id behavior, or latency/caching traits.

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 dense sentence, front-loaded with the resource and key, followed by the returned fields. No filler or restatement of the tool name, and every clause carries information.

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?

With an output schema present and full schema coverage on both parameters, the definition covers what an agent needs to invoke the tool correctly. The remaining gap is the unexplained language parameter behavior, which is minor given the otherwise complete picture.

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%, so both parameters are already documented, and the description's note that the id comes from list_route_ideas merely echoes the schema text. It adds no meaning for the language parameter — notably, it never says the returned content is localized to that ISO code, which is the one behavioral fact worth surfacing.

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 names a specific resource (a full travel route idea) and its retrieval key (by id), and it explicitly distinguishes itself from the list sibling by noting the id comes from list_route_ideas. An agent can tell this is the detail-fetch counterpart to the listing tool without opening either schema.

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 states the prerequisite workflow implicitly but clearly: the id must come from list_route_ideas, which is the key routing information an agent needs. It does not name any when-not condition or an alternative detail tool (e.g., get_hotel, country_guide), so it falls short of full explicit guidance.

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