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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, and the description is consistent with them while adding value: it discloses that the tool returns a procedural guide, takes no action, and requires a follow-up Cloud Browser session. The note on the restricted official Inventory API explains why browser automation is the route, though it is somewhat tangential and does not describe the shape of the returned guide beyond 'step by step'.

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?

Three sentences, front-loaded with the purpose and the critical 'returns instructions, does not act' clarification. The final sentence about the ClassPass Inventory API is informational justification for the browser-based approach rather than essential invocation guidance, making it slightly longer than strictly necessary.

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-only tool with no output schema, the description covers what it returns (screens, buttons, fields), that it has no side effects, and which tool family executes the action. The only gap is that it does not say which cotlet_browser_* call opens the ClassPass Cloud Browser first, leaving the agent to infer the entry point.

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 the baseline is 4 and there is nothing for the description to disambiguate. It correctly implies no inputs are required to obtain the instructions.

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 states a specific verb and resource ('Mark attendance in the user's own ClassPass account') and immediately clarifies the crucial nuance that the tool only returns a step-by-step guide rather than acting itself. It does not name any sibling tool (e.g. classpass_book_class or classpass_list_reservations) to contrast against, so differentiation comes from the described output rather than explicit sibling comparison.

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?

It gives a clear workflow: call this first to get screens/buttons/fields, then execute with the cotlet_browser_* tools in the user's ClassPass Cloud Browser, and explicitly notes it 'opens nothing by itself.' That is an explicit when-to-use and an explicit exclusion (no action performed). There is no guidance on adjacent alternatives such as checking existing reservations or what to do if attendance is already recorded.

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