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

The description's 'MUTATES' warning is consistent with destructiveHint=true and adds the concrete write endpoint and expected return value, which annotations do not cover. It omits meaningful side effects an agent would want to know — slot-availability conflicts, attendee notification emails, and uniqueness/duplicate handling.

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 tight sentences that front-load the mutation warning, then required fields, then the passthrough escape hatch. No filler and nothing buried at the end.

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 mutation tool with no output schema, it does the right things: states the return value, the transport, and the required/optional split. The remaining gap is failure behavior — what happens when the requested slot is taken, or whether the call is idempotent — which matters for a booking-creation write.

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%, so the baseline is 3; every parameter already has a description. The one genuine addition is routing complex payloads (`answers`, `linkFields`) through the `fields` passthrough, which is not evident from the schema's generic merge wording. Everything else (ISO 8601, IANA time zone) merely repeats the schema.

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 ('creates a booking (appointment) on a profile') plus the exact API route POST /v1/bookings. This is unambiguously distinguishable from siblings like create_appointment_type, update_booking, or cancel_booking.

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 'MUTATES ... creates' framing and the explicit required-field list give a clear precondition for invoking it. It never names alternatives (e.g. use update_booking to modify an existing booking, or list_bookings to check for conflicts), so it stops short of full when/when-not guidance.

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