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

Goes well beyond the annotations by disclosing the payment lifecycle: the diamond is held immediately, spent only when Ben's calendar confirms (usually within a minute), and returned if the hour is not booked. It also notes the booking carries its own label and can be moved or cancelled before the hour starts, which is exactly the mutation context an agent needs.

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-loads the core action and the payment consequence, and every clause carries information. The parenthetical asides make it slightly dense and run-on, but nothing is padding.

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 mutating booking tool with no output schema, it covers cost behavior, timing, refund semantics, and post-booking options. What the response contains is only gestured at ('its own label'), leaving the agent to infer the returned object's shape.

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 applies. The description reinforces the critical start-passing constraint and the label convention, but it adds little about topic or timeZone beyond what the schema already documents, so it does not materially exceed the schema's own guidance.

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: spending a diamond to book a one-to-one hour with Ben, with scope constrained to an open hour from my_bookings. This clearly separates it from book_intro_call and the event/cohort booking siblings without needing their 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 an explicit prerequisite (the start must come from my_bookings, passed exactly as listed) and names the follow-up alternatives move_booking and cancel_booking with the conditions that select them. It does not explicitly contrast with book_intro_call, which is the main remaining gap.

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