cancel_transaction

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

Without annotations, the description carries the full burden. It discloses the exact behavioral mechanism — sending a 0-value self-transaction with a higher gas price — which goes beyond just saying 'cancel'. It omits some edge-case caveats (e.g., failure if the original tx is already mined, gas cost implications), but the core behavior is transparent.

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?

A single, front-loaded sentence. No filler. The essential action and method are clear.

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 tool has a modest complexity with four parameters and no output schema. The description explains the purpose and mechanism, but it doesn't mention failure conditions, network defaults, or how this relates to speed_up_transaction. Still, it's complete enough for an agent to select it.

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 provides 100% coverage for all four parameters. The description adds meaning by explaining how the parameters fit together: the originalTxHash identifies the transaction to be replaced, privateKey signs the self-transfer, and gasPriceMultiplier controls the higher gas price. This enriches the schema descriptions.

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 opens with a specific verb ('Cancel'), identifies the resource ('a pending transaction'), and explains the mechanism ('sending a 0-value transaction to yourself with the same nonce but higher gas'). This clearly distinguishes it from sibling tools like speed_up_transaction.

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 establishes a clear condition: it only applies to 'a pending transaction'. This implies when to use it, but it doesn't explicitly contrast with alternatives like speed_up_transaction or state exclusions (e.g., not for confirmed transactions).

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