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

Annotations already declare destructive=true, idempotent=true, and openWorld=true, so the safety profile is partly covered. The description adds real value by disclosing the validation rule (new time must come from get_availability, own slot excluded) and the failure mode ('otherwise conflict'), which the annotations do not convey.

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 tight sentences with the core action front-loaded and the constraint second. The parenthetical about the appointment's own slot is dense but earns its place by preventing a real error.

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 3-param mutation tool with no output schema, annotations cover safety/idempotency and the description covers the key validation and conflict behavior. Missing are auth/permission requirements and confirmation that the returned state is the updated appointment, but nothing critical to invoking it correctly is absent.

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 only 33% (only startTime is documented as ISO 8601). The description clarifies that doorId is optional and re-frames startTime as a movable start, which partially compensates, but appointmentId is never explained and the schema still carries most of the burden poorly.

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 (move/reschedule) and resource (a confirmed appointment) plus the two fields being changed (start time, door). It does not explicitly distinguish itself from the overlapping sibling update_appointment_details, but the 'confirmed appointment' scope and the get_availability linkage make the intent clear.

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?

Usage is only implied: the agent can infer this is for changing the time/door of an already-confirmed appointment, and the description states the validity rule for the new time. It never says when to prefer this over update_appointment_details or cancel_appointment, and gives no explicit exclusions for non-confirmed appointments.

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