verify_vault

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

The description adds substantial behavioral context beyond the annotations: it discloses refusal behavior (survives=None, reconstruction='unreliable') and specific triggers (donation/flash-loan attack, short history, APY outside sane band). It also mentions 'Keyless on Base,' revealing operational requirements. This goes well beyond the readOnly/idempotent hints.

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 two sentences, front-loaded with the core action, and every clause adds value: the derivation method, the 'no self-report' distinction, the refusal conditions, and the keyless operational factor. 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?

Given the tool's complexity and lack of output schema, the description covers the main behavior, refusal modes, and operational context. It explains what happens in failure cases but does not specify the success output shape (e.g., what the derived APY looks like). The annotations and schema fill many gaps; the description is reasonably complete.

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 has 100% parameter description coverage (chain default, vault address, api_key). The description adds no additional parameter-specific meaning beyond the schema, so baseline 3 is appropriate. It does not elaborate on parameter formats or constraints not already in the schema.

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's function: fetching price-per-share history from Deposit/Withdraw events and re-deriving realized APY. It distinguishes itself from siblings by focusing on vaults and on-chain derivation ('no self-report'). The verb 'RE-DERIVE' is specific and the resource (vault APY) is explicit.

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 usage for verifying a vault's APY independently of self-reporting. It provides explicit conditions under which the tool refuses to sign, which guides when results may be unreliable. However, it does not explicitly mention alternatives or when to choose this over sibling tools, though the 'no self-report' phrasing suggests a contrast with self-reported data.

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