Describe a Populi API route

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

Annotations already cover safety (readOnly, idempotent, closed-world), so the description's job is to add context — and it does, by disclosing that the response is metadata including required Populi roles and a docs link, which tells the agent this is a documentation lookup rather than a data fetch. It doesn't describe size/format of the reference payload, but with readOnly+idempotent declared that gap is minor.

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 sentence that front-loads the payload contents and closes with the two ways to invoke it. No filler, nothing repeated from the schema verbatim.

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?

No output schema exists, but the description enumerates the return contents (placeholders, typed params, expandable properties, filters, roles, docs link), so the agent knows what to expect. All three optional parameters are covered and the read-only nature is declared via annotations.

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 baseline is 3, but the description adds genuine meaning: it distinguishes the id-based lookup from the combined method+path lookup and indicates the id comes from populi_search_api. That relationship (id alone vs. method and path together) is not stated in 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?

States a specific verb+resource ('Full reference for one route') and enumerates exactly what the reference contains: placeholders, parameters with types, expandable properties, filter conditions, roles, and a docs link. This makes it unambiguous against siblings like populi_get (fetch data) and populi_search_api (find routes) without needing 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?

'Pass a route id from populi_search_api, or a concrete method and path' gives clear entry conditions and points at the sibling that produces valid ids. It stops short of any exclusion (e.g. 'use populi_get instead if you already know the route and want data'), so it is clear context without explicit when-not guidance.

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