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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false, and the description usefully resolves the resulting ambiguity by stating the appointment is 'kept rather than deleted' — i.e. destructive means state change, not removal. It also discloses that the return indicates whether the salon's cancellation message goes to the client. It does not mention permission requirements or the refusal behavior, though the schema covers the latter.

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 short sentences with the use case front-loaded, followed by behavioral facts and then the exclusion. No filler and nothing that repeats the title verbatim.

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 two-parameter mutation with an output schema, full schema coverage, and rich annotations, the description supplies everything an agent needs: purpose, soft-delete semantics, return signal, and the sibling exclusion. No material gap remains.

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% and both parameters are documented in the schema, including the concurrency-refusal behavior of expectedLastEditTime. The description adds no parameter-level detail, so the baseline of 3 applies.

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 names a specific verb and resource ('cancel a client's appointment') and immediately distinguishes it from the closest sibling by stating 'Not for moving an appointment to another time,' which rules out reschedule_appointment. An agent can pick this tool without opening either schema.

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 an explicit trigger ('when someone asks to cancel a client's appointment') and an explicit exclusion for rescheduling. It does not name the alternative tool by name or cover edge cases such as already-canceled appointments, so it falls just short of full routing guidance.

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