prepare_revoke_approval

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

Beyond annotations (destructiveHint, idempotentHint), the description adds crucial details: pre-flight check that refuses zero allowances, resolution of friendly spender labels, inclusion of previous allowance in description, and EVM-only constraint. This gives the agent a complete picture of the tool's behavior.

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 well-structured and concise, with each sentence adding unique value. It front-loads the core action, then covers pre-flight checks, label resolution, and TRC-20 distinction. No redundant or irrelevant information.

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?

Given the tool's complexity (4 parameters, no output schema), the description is quite complete. It explains the output (unsigned transaction) and workflow, but could be slightly more explicit about the return structure (e.g., that it returns a transaction object). However, it covers the key aspects for an agent to use it correctly.

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 input schema already provides good descriptions for wallet, token, and spender. The description adds value by explaining the label resolution for spender and that the tool includes the previous allowance in the preview. This enhances semantic understanding beyond the schema alone.

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 clearly states the tool builds an unsigned approve(spender, 0) transaction to revoke an allowance. It specifies the resource (allowance on token for spender) and distinguishes from siblings by noting EVM-only and TRC-20 is handled by a different tool. The verb 'revoke' is specific and matches common user intent.

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 explicitly advises pairing with get_token_allowances to list current approvals. It warns against using when the allowance is already 0, calling it a likely wrong pair. It also points to prepare_tron_trc20_revoke for TRC-20 tokens, providing clear alternatives.

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