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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=true, idempotentHint=true), but the description adds auth scope requirements that aren't in the structured data: COMPLETED/NO_SHOW need appointments:receive while CONFIRMED needs appointments:write. It does not explain side effects or what a destructive transition implies, so it stops short of a 5.

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, front-loaded with the core action and enum, then permissions, then the sibling routing. Every clause carries distinct information with no filler.

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?

Covers action, valid values, authorization scopes, and the cancel alternative, which is sufficient for a 2-parameter mutation with no output schema. It omits any statement about reversibility or side effects of the transition, which would be the remaining gap.

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 0%, but the description restates the enum values already present in the schema and adds real meaning by mapping each status to its required permission. appointmentId is left entirely undocumented in both schema and description, so compensation for the coverage gap is partial.

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 ('Transition an appointment's status') and enumerates the exact target states, so its scope is unambiguous. It distinguishes itself from cancel_appointment by name, which is the nearest sibling that could otherwise be confused with a status change.

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?

Explicitly routes cancellation to cancel_appointment, giving one clear alternative for the most confusable operation. However, it does not address the neighboring state-changing siblings (approve_appointment, reject_appointment, check_in_appointment, mark_arrived), so an agent still has to infer whether those overlap with the CONFIRMED/COMPLETED transitions.

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