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

Annotations only declare that this is a non-idempotent, non-destructive, open-world write. The description adds genuinely new behavior: a Stripe payment link may be returned, the slot is held for 30 minutes and only booked once paid, a deposit/full payment may be required, and the phone must be verified. These are the facts an agent needs to set expectations and sequence steps.

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 the action and the source of each input, then prerequisites, then payment behavior, then the sibling route-out. Dense with substance, though it runs long and could tighten the payment-policy sentence without losing meaning.

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?

Despite having no output schema, the description tells the agent what comes back (a secure Stripe payment link), how long the hold lasts, and what the client must do. For a 7-param booking write tool, this is complete enough to invoke correctly end to end.

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 57% and the description compensates well for the important ones: pro_id's provenance (find_pros_to_book), time's format source (pro_open_times), and the optional tip tied to the payment. It adds little for name and notes, which remain thin, but the load-bearing parameters are clarified.

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 ('Book the client a NEW appointment with a pro') and pins the inputs to their sources (pro id or booking handle from find_pros_to_book, time from pro_open_times). It explicitly distinguishes itself from reschedule_my_booking, so an agent can route correctly without opening schemas.

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 explicit preconditions (confirmed mobile via verify_my_phone, client must be told the booking policy and give OK) and names the alternative for the change case ('never book a second one: use reschedule_my_booking'). When-to-use and when-not-to-use are both covered.

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