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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds real behavioral context beyond that: includeSimilar costs 'one extra upstream call', the provider result carries a processing status, and it enumerates the returned data domains.

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?

The identifier and purpose are front-loaded, and the includeSimilar behavior is isolated in its own sentence. The middle field enumeration is long but each item is informative rather than filler.

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 no output schema, the description carries the return-value burden and largely discharges it by enumerating the detail categories. Annotations cover the safety profile; the only real gap is what happens when a code is not found or ambiguous.

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 the baseline is 3. The description still adds meaning the schema lacks: includeSimilar returns 'up to 8 similar courses' (a concrete cap not in the schema) and confirms the identifier can be a code, URL or slug.

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 ('Full details of one course') and names the exact identifiers accepted (CRICOS code, oneuedu.com URL/slug). This clearly distinguishes it from the sibling search_courses, which is a list/search operation.

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 makes the use case clear: retrieving full detail for a single known course, with includeSimilar as an opt-in expansion. It never names search_courses as the alternative for discovery, nor states any exclusions, so it falls short of a 5.

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