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

The description goes well beyond the annotations by explaining what the mutation does: it moves the booking, preserves history, frees old capacity, and sends transactional notifications. It also flags the one-time nature of the approval and the idempotency requirement for safe retries. This is rich behavioral context with no contradiction against the annotations.

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?

Three focused sentences with no filler. The critical precondition is front-loaded, the effects are summarized efficiently, and the idempotency note is placed at the end where it is still discoverable. Every sentence earns its place.

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?

The description provides the key operational context: the approval gate, the effects of the reschedule, and retry behavior. An output schema exists, so return values do not need explanation. It is slightly incomplete in that it leaves three required parameters unexplained and does not explicitly state how the 'reserved available time' was created or that a prior preparation step is expected.

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 description coverage is only 20%, so the description must compensate. It does add meaning for booking_change_authorization_token ('one-time approval') and idempotency_key ('safe retries must reuse the same key'), but it says nothing about source, anonymous_session_id, or correlation_id, leaving those three required parameters semantically unexplained.

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 clearly states this tool reschedules an existing booking by moving it to a reserved time, and the title names the target action. It also describes distinct effects—preserving prior-time history, freeing old capacity, sending notifications—that differentiate it from siblings like cancel_service_booking or create_service_booking.

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 phrase 'Use this only with the one-time approval issued after the user confirms the exact reschedule' gives an explicit precondition and a clear when-to-use gate. Retry guidance is also provided. However, it does not explicitly name or contrast alternative siblings such as prepare_service_booking_change, so the differentiation is inferred rather than explicit.

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