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

The annotations already mark destructiveHint: true. The description adds valuable context: modifies the calendar and may send cancellation emails unless suppressed. This informs the agent of side effects beyond the annotation.

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?

Two sentences with no wasted words. The first sentence is front-loaded with the primary action, and the second adds critical side-effect context. Format is efficient.

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?

The description covers purpose, side effects, and references the REST endpoint. For a tool with no output schema, it could mention expected return values or error cases, but the current level is adequate given the simple cancellation operation.

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% with clear descriptions for each parameter. The description does not add extra semantic meaning beyond what is in the schema, so the baseline score 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 clearly states the action ('CANCELS an existing appointment') and the resource (appointment). It distinguishes from siblings like acuity_reschedule_appointment by specifying cancellation, and mentions side effects (calendar modification, possible emails).

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?

The description implies when to use (to cancel an appointment) but does not explicitly contrast with alternatives like rescheduling or provide conditions (e.g., appointment must exist, permissions required). It offers no guidance on when not to use.

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