Cancel transaction request

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

Annotations already signal destructive/non-read-only behavior, so the bar is lower. The description adds valuable context by specifying exactly what is affected (the pending browser approval request) and adding the 'still-pending' state requirement, which goes beyond the basic destructiveHint. This enriches the agent's understanding of the tool's effect.

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?

The description is a single, seven-word sentence that is front-loaded with the verb and object. It contains no filler words or redundant information. Every word contributes meaning, making it exemplary in conciseness.

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 simple one-parameter tool with annotations, the description covers the core action and state condition. However, it does not explain what happens when the request is not pending, nor does it clarify how to obtain the requestId. Given the absence of an output schema and the tool's simplicity, the description is adequate but has clear gaps in error handling and parameter linkage.

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?

The schema has zero description coverage for the only parameter, requestId, and the tool description does not mention it at all. The description fails to compensate for the low schema coverage, leaving the agent to infer that requestId is the identifier of the request to cancel from the tool name. This is a minimal, but not absent, semantic connection.

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 uses the specific verb 'Cancel' and identifies the resource as 'a still-pending browser approval request,' which clearly distinguishes it from sibling tools like request/review or list transactions. The qualifier 'still-pending' adds precision about the target state. This is a clear, specific purpose statement.

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 implies when to use the tool: for cancelling a request that is still pending approval. It also implicitly excludes non-pending requests, serving as a usage condition. However, it does not explicitly reference alternatives or explain when not to use it beyond the pending-state constraint, so it falls short of a 5.

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