List courses

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description still adds real behavioral value by disclosing the return shape (code, title, CFU, progress) and the null-progress semantics, which matter for a tool with no output schema. It omits ordering and pagination, keeping 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?

A single sentence that front-loads the action and resource, then packs the returned fields plus the null edge case. Every clause carries information and there is no 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?

For a zero-parameter read tool with annotations covering safety and no output schema, the description supplies the field-level return contract an agent needs to interpret results. Missing only secondary details such as result ordering or empty-enrollment behavior.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; baseline for a 0-param tool is 4. The description correctly implies a no-argument call scoped implicitly to 'the student'.

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 ('List') and resource ('the student's enrolled courses'), and enumerates the returned fields (code, title, CFU, progress). This clearly separates it from list_lessons and get_lesson, though it never names those siblings explicitly.

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?

Usage is implied: call it to enumerate the student's enrolled courses, and the 'null if not started' note hints at the no-activity case. There is no explicit when-to-use vs. when-not, and no routing away from the overlapping sibling course_progress.

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