Check whether you can take a course

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

Annotations already declare this as read-only, non-destructive, and idempotent, so the safety profile is covered. The description adds useful behavioral context beyond annotations: it reports both satisfied and missing requirements, and it discloses the limitation that enrollment restrictions cannot be automatically verified by the API.

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 description is two sentences with no filler. The primary evaluation behavior is front-loaded, and the additional enrollment-restriction note is concise and informative without being redundant with the schema or annotations.

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 read-only eligibility-check tool with fully documented parameters and safety annotations, the description covers the core behavior, scope, and a key limitation. There is no output schema, but the description gives enough about what is reported (met/missing requirements and restrictions) to guide an agent, though exact return structure is left unspecified.

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 100%, so the parameters are fully documented in the schema. The description reinforces the role of 'completed' courses and mentions enrollment restrictions, but it does not add meaningful detail about apScores or the precise input formats beyond what the schema already provides. Baseline 3 is appropriate.

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 ('Evaluate') and resource ('a course's prerequisite tree') and clearly states the output: which requirements are met and which are missing. It also adds a distinct second purpose, enrollment restrictions, making it easy to distinguish from sibling tools like get_course or course_grades.

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 provides clear context that this tool is for checking prerequisite and enrollment eligibility against a student's completed courses. It does not explicitly name alternative tools or state when not to use it, but the intended scenario is obvious and no misleading exclusions are present.

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