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

With no annotations, the description carries the full burden, and it does disclose one genuinely important trait: the route is not executed. It says nothing about what happens for an unknown path, whether auth is required to inspect paid routes, or what form the description takes.

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 short sentences, no filler, and the core scope statement comes before the non-invocation caveat. Nothing is wasted given how simple the tool is.

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 one-parameter lookup this is close to adequate, but there is no output schema, so the description should indicate what 'describe' actually returns (parameters, pricing, docs?) and it does not. The agent knows what to pass but not what it will get back.

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% and the single required parameter already carries the exact same example ('such as /iban') in its description, so the description adds no syntax or format detail beyond the schema. Baseline 3 applies when the schema does the work.

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?

States a specific verb and resource ('Describe one paid route') plus the selector ('by path, such as /iban'). 'One' implicitly contrasts with the sibling list_routes, though the sibling is never named, so differentiation is inferential rather than explicit.

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?

'Does not call it' usefully signals this is metadata lookup rather than invocation, which is the key usage distinction an agent needs. However, it never names list_routes as the alternative for discovery or states preconditions (e.g. the route must exist), leaving selection guidance implied.

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