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

Goes far beyond the annotations by disclosing the full outcome space ('confirmed', 'pending', 'awaiting_payment' with amount, currency, expires_at and payment_handlers), the place-hold semantics until expires_at, the default payment-at-venue rule, the one-time status_token, and duplicate-call rejection. This is exactly the behavioural context an agent needs before a write call.

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 purpose is front-loaded in the first clause and every subsequent sentence carries distinct information (recipient of contact data, outcome statuses, payment branch, credentials returned, duplicate rule). It is a dense single paragraph with nested parentheticals, which costs a little readability but no sentence is 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 9-parameter write tool with no output schema, the description supplies everything missing: return values (booking_id, status_token), all possible result statuses, the payment branch, hold expiry, and retry/duplicate behaviour. An agent could invoke and handle the response correctly from the description alone.

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 meaning: slot, service_id and business_id are tied to the specific sibling tools that produce them, and the duplicate-rejection rule explains how retries behave (interacting with the optional idempotency_key). It does not explain the note field or quantity bounds, which the schema already covers.

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 booking for one open slot on behalf of the customer') and immediately scopes it with prerequisites (customer agreement on service, time, quantity, contact details). It is clearly distinguished from siblings by naming get_availability, get_business, get_booking_status, complete_booking and modify_booking as separate steps.

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 gives a clear precondition ('after the customer has agreed...') and points to the source tools for its inputs (slot from get_availability, service_id from get_business). It also implies the follow-on path via complete_booking when payment is pending, but never states an explicit exclusion such as 'use modify_booking to change an existing booking'.

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