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

The description goes well beyond the destructiveHint annotation by clarifying this is a PATCH partial update, that the bookingId is path-only and never sent in the body, and that `fields` is a passthrough for additional documented fields. These are concrete behavioral details that help the agent call the API correctly.

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?

The description is compact and front-loaded with the mutating nature and purpose, then adds protocol details and field guidance without fluff. Every sentence earns its place, and the most important routing information appears first.

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?

With 10 parameters, a destructive annotation, and no output schema, the description is largely complete: it covers purpose, HTTP method, partial-update behavior, supported fields, the passthrough mechanism, and path handling. It does not describe the response shape, but the described PATCH semantics plus schema coverage give enough context for correct invocation.

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?

Since schema coverage is 100%, the baseline is 3, and the description adds extra meaning by grouping the updatable fields, explaining the partial-update semantics, and highlighting the `fields` passthrough for answers/linkFields. The path-vs-body distinction for bookingId is also valuable beyond the schema description.

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 states a specific verb and resource: it 'updates an existing booking' and gives concrete use cases (reschedule, rename, mark cancelled/no-show). This clearly distinguishes it from create_booking, get_booking, and cancel_booking, even though cancelling can also be done via the cancelled field.

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 clearly indicates this tool is for mutating an existing booking and lists which fields can be set, so an agent knows when to invoke it. It does not explicitly name alternatives like cancel_booking or create_booking or state when not to use this tool, but the context is clear enough.

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