Cancel a ClickBus booking (gated)

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

The description adds valuable behavioral context beyond the annotations: the tool is fail-closed, requires a specific environment permission, and rejects guest-token charge attempts. This complements the destructiveHint=true annotation and helps the agent understand safety and auth boundaries before invoking it.

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 short sentences, front-loaded with the most critical behavioral keyword 'Fail-closed' followed by the two required gates. Every sentence earns its place with no repetition of schema or annotation details.

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 gated destructive mutation, the description covers the necessary safety and authorization context well. Since there is no output schema and the tool's core action is in the title, the lack of details about return values or post-cancel effects is a minor gap rather than a blocking one.

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 33%, and the description does not compensate. It mentions explicit_user_intent as a requirement, but the schema already describes that parameter. booking_id and response_format are left to their property names, with no added meaning about formats, behavior, or dependencies.

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 title clearly states the action and resource: 'Cancel a ClickBus booking (gated)', which distinguihes it from sibling tools like search and book. The free-text description itself does not restate the purpose, but combined with the title and tool name the meaning is unambiguous.

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 description gives concrete usage gates: requires CLICKBUS_ALLOW_MUTATIONS and explicit_user_intent, and guest tokens cannot charge. It does not explicitly name alternative tools or when-not-to-use scenarios, but for a cancel operation these preconditions are clear and actionable.

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