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

Goes well beyond destructiveHint=true: it declares the operation as a write, warns that Reservio may notify the client, states it is not idempotent ('a second call books a second appointment'), and names the underlying POST endpoint. These are exactly the behavioral traits an agent needs before mutating state.

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?

Single dense sentence stack, front-loaded with the 'WRITE:' marker and the slot-prerequisite before the side-effect warnings. 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?

For a mutation with no output schema, it covers side effects, idempotency, prerequisite slot retrieval, and the API path. The one gap is that it never indicates what the agent gets back (e.g., a booking id), which matters for follow-up calls.

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 83%, so start/end/service_id/client/business_id are already documented, including the business_id default-to-login behavior. The description only implies service and start/end, adding no syntax or constraint detail beyond the schema, so the baseline of 3 applies.

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 ('create a real appointment booking for a service') plus temporal scope ('at a start/end time'), which cleanly separates it from the group-booking sibling. An agent knows exactly what is produced without opening the 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?

Explicitly tells the agent to source the time from reservio_get_booking_slots, establishing a prerequisite workflow. It does not explicitly rule out reservio_create_group_booking, so the alternative-selection guidance is clear but not complete.

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