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

Annotations only declare destructiveHint=true, so the description usefully adds that a late cancel 'can trigger the business's penalty rules' and that the response reports whether the cancel counted as late. This is real behavioral context beyond the safety hint, though it omits anything about permissions or irreversibility of the removal itself.

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 compact sentences: purpose first, then the risky parameter's caveat, then the response hint and endpoint. No filler or repetition.

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 3-parameter destructive mutation with no output schema, the description covers purpose, the risky flag's consequence, and what the response conveys. It could say more about what the removal destroys (e.g. attendance/booking record) or required permissions, but it is largely sufficient.

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 the baseline is 3, but the description goes slightly beyond the schema by framing is_late_cancel as something that can trigger penalty rules and should be left unset by default, reinforcing the safe default rather than merely restating the parameter.

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+resource ('Cancel a customer's booking for a class or appointment') and names the exact API operation (POST /events/{id}/unregister). It is immediately distinguishable from the inverse sibling goteamup_register_customer_for_event.

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?

Gives explicit conditional guidance for is_late_cancel ('leave it unset unless asked') and describes the consequence of setting it. It doesn't explicitly name register_customer_for_event as the inverse alternative, but the context is clear enough for an agent to act on.

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