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

Annotations already declare destructiveHint=true, idempotentHint=false and openWorldHint=true. The description adds useful behavioral context beyond that: the server only acts when bookingId and email match the booking, which is a verification/authorization trait not visible in structured fields. It stops short of describing refund timing, reversibility, or failure modes.

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?

Two short paragraphs, the action and the mandatory pre-step front-loaded, with zero filler. Every sentence carries either the operation or a constraint.

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 destructive mutation with no output schema, the description covers the precondition, the credential-matching rule, and the sibling to consult first. It leaves the post-cancellation result (confirmation, refund mechanism) to be inferred, which is a minor gap.

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 100%, so both required parameters and the optional lastName are already documented in the schema. The description restates the email-matching rule but adds no syntax, format, or ID-source detail beyond what the schema provides. Baseline 3 is correct here.

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 ('Cancel a confirmed tour or activity booking') and names the exact sibling it must not be confused with implicitly via the tour/activity scope, versus cancel_hotel_booking. An agent can route correctly without opening either 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 an explicit precondition and sequencing rule: first show the refund from getExperienceBookingCancelPreview and wait for a clear yes. It also states the matching requirement for bookingId and email, so the agent knows both when to use this tool and what must be true before calling it.

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