prepare_course_registration

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds the key behavioral fact that no enrolment occurs and that it is a preview step, which is useful but does not go much beyond what annotations and the tool name suggest.

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, front-loaded with the core purpose and immediately followed by the key non-enrolment caveat. Every word earns its place and there is no redundant restatement of the tool name.

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 single-parameter read-only preview tool, the description covers what is previewed, the no-enrolment guarantee, and the expected flow before confirmation. Since there is no output schema, the description partially describes the output by naming membership state and available enrolment action, which is adequate for this complexity level.

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 description coverage is 0%, so the description must compensate, but it does not explain the courseUrl parameter beyond the parameter's own self-explanatory name. It hints that the tool identifies an exact course, but does not clarify what kind of URL is expected, where to obtain it, or how it relates to the previewed course/code/semester.

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?

The description uses a specific verb ('Preview'), a specific resource ('an exact Discover course'), and states the outcome (course, membership state, available enrolment action). It also explicitly disclaims enrolment ('Does not enrol'), which clearly separates it from sibling confirm_course_registration.

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 phrase 'before confirming' gives clear sequencing context and the disclaimer 'Does not enrol' implies this is the safe pre-confirmation step. It does not explicitly name the alternative tool, but the context is sufficient for an agent to infer when to call it.

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