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

Annotations already flag destructiveHint=true, idempotentHint=false and openWorldHint=true, and the description adds value beyond them by spelling out the external third-party side effect (a notice emailed/messaged to the order's customer) and the fee/slot consequences. It does not address what happens on a repeat cancel of an already-cancelled appointment, which matters given idempotentHint=false.

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, front-loaded with the action, then the notify decision, then the risk, then the endpoint. No filler and nothing buried.

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 destructive two-parameter mutation with full schema coverage and no output schema, the description covers purpose, both notify branches and the risk profile. Remaining gaps (auth/permission requirements, behavior on an already-cancelled appointment) are minor but real.

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% and both parameters are already documented in the schema, including 'Required: decide explicitly' for notify. The description restates the notify outcome and adds only the third-party framing, so baseline 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?

States a specific verb and resource in caps ('CANCEL an appointment') and pins the underlying operation ('PUT /appointments/{id}/cancel'). It is not explicitly differentiated from the sibling aryeo_reschedule_appointment, so an agent must infer that one moves the booking and the other kills it.

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 real decision context: the notify flag's meaning and the consequences of cancelling (possible fees, slot released). It does not state when to prefer an alternative such as aryeo_reschedule_appointment when the customer wants a different time rather than no booking.

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