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

Annotations only declare the mutation profile (readOnlyHint=false, openWorldHint=true, idempotentHint=false, destructiveHint=false); the description adds the operationally important facts: nothing is confirmed until the business answers, no payment is taken, the business is notified immediately, and the customer receives two emails. That is meaningful behavior beyond what the structured fields provide.

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-loaded with purpose and non-confirmation status, then prerequisites, then what happens next — a logical order with no filler. It runs long and repeats the email rationale already present in the schema, but every sentence carries usable 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 9-parameter, nested-object mutation tool with no output schema, the description supplies exactly what is missing: the async confirmation flow, the no-payment guarantee, and the source of each dependent value. An agent can call this correctly and set expectations for the caller.

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, but the description adds cross-tool meaning: start must come from get_availability unchanged, answers must be keyed by question id from list_services, address is conditional on an at-customer-address service, and email is the channel the confirmation arrives on. It does not explain the checklist joining convention or staff_id, which the schema handles.

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 — 'Send 904 Digital Media a booking REQUEST for one appointment on the customer's behalf' — and immediately clarifies that this is a request, not a confirmation. That framing distinguishes it from siblings like get_availability and list_services without the agent needing to open 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?

Explicitly says to use a start from get_availability, to pull answers from list_services by question id, and to fall back to request_callback when the customer will not share an email. Both the positive path and the exclusion are named.

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