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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=true, openWorldHint=true), so the description only needs to add context. It does add real value: the three outcome states (confirmed, pending with the business confirming, failed) and the fact that a reference is returned. It omits any auth or rate-limit behavior, keeping it short of a 5.

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 sentences, no waste, and the core purpose is front-loaded before the precondition and the return-value note. Every sentence adds information an agent needs.

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 no output schema, describing the confirmed/pending/failed returns and the reference is exactly the right compensation, and the confirmation gate is covered. It falls short only on the seven undocumented input parameters, which an agent still has to infer.

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 0% across 9 parameters, so the description carries the full burden — yet it only clarifies customer_confirmed (and implicitly start, by tying it to check_availability). business_id, service_id, customer_name, notes, agent_name, customer_email and customer_phone are left entirely undocumented in both schema and 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?

States a specific verb+resource ('Book a time') and ties the resource to the sibling check_availability, so an agent can distinguish it from cancel_booking, request_quote, and the rest without opening a schema. The dependency on a prior availability result makes the scope unambiguous.

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?

Gives an explicit precondition: use only after the customer has said yes to this exact business, service and time, and set customer_confirmed=true to signal it. That is strong when-to-use guidance, though it never states when *not* to use it or names the alternative path (e.g. request_quote) for the unconfirmed case.

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