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

The description goes well beyond the readOnly/destructive annotations by disclosing side effects: free vs paid confirmation, hold expiry releasing the slot, host calendar insertion, invitee invitation delivery, and the importance of managing through manageUrl/token. It also exposes the 409 slot_unavailable behavior and recovery action.

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?

Dense but well-organized: the booking rule comes first, then payment/hold behavior, then side effects, then management handles, then error handling. Every sentence adds operational value; nothing 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?

Given the complexity of paid/free booking, hold expiry, calendar side effects, and series options, the description covers all critical decision points an agent needs. The absence of an output schema makes the explicit mention of paymentUrl, status, holdExpiresAt, manageUrl, and token especially valuable.

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 high at 75%, but the description adds essential meaning to `start` by requiring it to be one of the slots from get_available_slots. The repeat parameter is also enriched by the 'check_series first' and 'all or nothing' guidance, going beyond the raw schema constraints.

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?

The description opens with "Books `start`", naming a specific verb and resource, and immediately ties the booking to slots from get_available_slots. It clearly distinguishes creation from the later cancel/reschedule sibling operations by explicitly naming manageUrl and token as the means for those actions.

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?

It tells the agent to use a `start` value from get_available_slots, and the repeat field in the schema points to check_series first for series bookings. It does not explicitly say 'use this instead of X', but the workflow context and references to siblings give clear practical guidance.

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