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

Adds substantive behavior beyond the annotations: the client is not emailed, money does not move through the assistant, and the operation is a preview until confirm=true. These are exactly the side-effect facts an agent needs before mutating a booking, and they are consistent with destructiveHint=true / readOnlyHint=false.

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?

Four short sentences, front-loaded with the action, then the two behavioral caveats and the confirmation gate. No filler; every sentence carries 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?

For a three-parameter mutation with no output schema, this is complete: it covers the mutation, its side effects (no email, no money), and the two-phase preview/commit contract. Nothing required to call it safely is missing.

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 67% and the confirm parameter is already documented thoroughly in the schema, including the 'string true' edge case. The description reinforces the confirm gate but adds no syntax or constraint detail beyond the schema, so it sits at the baseline rather than compensating for the undocumented booking_id.

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 ('Move a booking to an open slot'), which cleanly separates it from siblings like book_session, cancel_booking, and find_open_slots. An agent can tell what it does and what it does not do (cancel, create) without opening the schema.

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 clear operating context: the slot must be open for the booking's length, and the call is preview-first. It does not name the alternative path (e.g. find_open_slots to obtain a valid new_start) or any when-not-to-use condition, so it stops short of explicit routing guidance.

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