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

Annotations cover the safety profile (not read-only, destructive, idempotent, open-world), and the description still adds real behavioral context beyond them: the carrier email side effect, the conflict behavior on non-PENDING input, and the required scope/role (appointments:write, Scheduler+). Nothing material about side effects or authorization is left implicit.

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?

Front-loads the core action and precondition, then alternatives, then side effects and scope. Six tight clauses with no filler; every sentence carries distinct information.

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 2-parameter mutation with no output schema, the description covers everything needed: precondition, conflict behavior, side effects, authorization scope, and a pointer that the updated appointment is returned. No gaps an agent would need to guess at.

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%, so both parameters (appointmentId, startTime with ISO 8601 format) are already fully documented. The description only restates that the time is optional and 'at a different start time', adding no format or edge-case detail beyond the schema. Baseline 3 applies when the schema does the heavy lifting.

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 (Accept), the resource (PENDING booking request), and the resulting state transition (PENDING → CONFIRMED), plus the optional time change. It explicitly names the sibling tools it is not (reject_appointment, reschedule_appointment), so an agent can disambiguate without opening any 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?

Gives the exact precondition ('Only for PENDING; otherwise conflict') and routes to the correct alternatives for the two adjacent cases: turning a request down and moving an already confirmed appointment. This is explicit when-to-use plus 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.