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

Annotations already cover safety (readOnly, non-destructive), and the description adds real behavioral context: results are newest-first, an empty list means no visits, and the call requires a Cotlet API key with access to this app. That auth prerequisite is meaningful beyond the annotations.

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?

"Newest first" is stated twice within the first two sentences, and "Returns the classes one person checked into" largely restates the opening clause. The auth note and empty-list semantics earn their place, but the redundancy costs a point.

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?

No output schema exists, so the description usefully covers return semantics (ordering, empty result) plus the auth prerequisite for a read-only tool. It is essentially complete for a simple three-parameter list call.

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 person_id and the from/to defaults are already documented in the schema. The description confirms the date-range concept but adds no format, boundary, or default semantics beyond what the schema provides — baseline 3.

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 a member's class check-ins) with scope bounded to a single person and a date range. The per-person scope implicitly separates it from zen-planner_get_class_roster, but no sibling is named 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?

"Run it once per person" gives a workflow hint, and the empty-list condition tells the agent how to read a null result. There is no explicit when-not guidance or named alternative (e.g. get_class_roster for a whole class), so usage is implied rather than spelled out.

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