approve

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

The description only states the action ('approve') and does not disclose behavioral traits such as that it sends a transaction, requires gas, needs wallet approval, or returns a transaction hash. The annotation openWorldHint indicates external side effects, but the description adds no additional context about the mutation or signing process. For a state-changing tool, this is insufficient.

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 one concise sentence, front-loaded with the key action and objects. No unnecessary words. It earns its place without being verbose.

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 mutation tool affecting the blockchain, the description provides only the basic action. It does not mention return values, transaction confirmation, errors, or any guidance on what happens after approval. With no output schema and minimal annotations, the agent gets little context beyond the schema fields.

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 provides full descriptions for all parameters (tokenAddress, spender, amount, chainId), so schema_description_coverage is 100%. The description itself adds no parameter semantics beyond what is already in the schema. Baseline 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?

The description clearly states the action (approve), the object (an amount of an ERC20 token), and the target (an address). It is unambiguous and uses a specific verb. However, it does not distinguish this tool from sibling tools like evm_approve_token_spending or approve_token_evm, which likely perform the same operation.

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?

There is no guidance on when to use this tool versus the many similar sibling tools. No prerequisites, preconditions, or alternatives are mentioned. The description simply states what it does, leaving the agent to infer usage context.

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