Course categories

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds value beyond them by disclosing the shape of what comes back (slug/name tree with child slugs) and how the response changes based on the `parent` argument. It does not mention rate limits or result-size bounds, which keeps it short of a 5.

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?

Three short sentences, front-loaded with the purpose, then the parameter branching, then the downstream handoff. Nothing is redundant with the annotations and no sentence is wasted.

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?

A single optional parameter, no nested objects, and no output schema, so the description carries the burden of explaining the return value — which it does by describing the slug/name tree and child slugs. Given the tool's low complexity, nothing an agent needs in order to call it correctly is missing.

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 schema already explains the omit-for-top-level behavior, so the baseline is 3. The description adds a real example ('e.g. programming') that clarifies the slug format and expected language, and restates the default/null branch in operational terms, which is marginal but genuine added 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?

States a specific verb and resource ('List Faradars course categories') and specifies the exact return shape ('a tree of slugs and names'), with a concrete example of the category vocabulary. An agent can immediately distinguish this discovery tool from the retrieval siblings like fr_search_courses and fr_course.

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 spells out both branches: omit `parent` for top-level categories, supply `parent` for that category's subtree. It goes further and routes the agent downstream by telling it to pass any returned slug as `category` to fr_search_courses, which is exactly the when-to-use-this-then-what guidance an agent needs.

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