cancel_transfer

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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the description carries less burden. It adds meaningful context beyond annotations by noting cancellation only works pre-completion, which is a behavioral constraint not evident from schema or annotations. No contradiction.

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?

Description is a single sentence that front-loads the action ('Cancel a transfer') and includes a necessary condition in a compact parenthetical. No wasted words.

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 mutation tool, the description provides sufficient context: what it does and a critical precondition. With annotations covering the destructive nature and no output schema required, the description is adequately complete for agent decision-making.

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?

Input schema fully documents transferId with description 'Transfer ID' (100% coverage). The description adds no additional parameter-level detail, so the baseline of 3 is appropriate.

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?

Description uses the specific verb 'Cancel' with the resource 'transfer', clearly distinguishing it from transfer retrieval tools like list_transfers and get_transfer. The parenthetical adds a key condition (not yet completed) that makes the action 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?

Explicitly states when cancellation is possible ('only possible if not yet completed'), giving the agent a clear precondition and implicitly telling it not to use this tool for completed transfers. Does not name alternative tools, but the condition is enough for basic guidance.

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