explain_signature

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

With no annotations provided, the description carries the full burden. It discloses limitations: does not run danger-primitive scan, does not simulate on-chain effects, and returns found=false with available function names when the name is missing. It also warns 'MUST NOT approve a pending signature', which is a critical behavioral constraint.

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-organized into PURPOSE, GUIDELINES, LIMITATIONS, and EXAMPLE sections. It front-loads the core purpose and each section is concise without filler. The length is justified by the tool's complexity and the need to differentiate from siblings.

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?

There is no output schema, so the description explicitly defines the return object: {found, function, sentence, tier, reason}. It also covers the failure case (found=false) and provides a concrete example. This makes the tool's behavior fully understandable without requiring additional context.

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?

Schema description coverage is 100% with all parameters already well-described. The description adds an example invocation and clarifies 'function' vs 'signature' usage, but this is largely redundant with the schema. No significant new parameter semantics are provided, so 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 tool's purpose: 'Review UX copy for ONE function of an ERC-7730 descriptor'. It specifies the resource (ERC-7730 descriptor), the action (review/explain), and the output. It also explicitly differentiates from siblings by noting it is not bound to chain/sender/calldata and does not approve signatures, distinguishing it from preflight_transaction, check_descriptor, and scan_contract.

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 gives explicit when-to-use guidance: 'Use this only while authoring or reviewing confirmation copy'. It also names alternatives: 'Use preflight_transaction for every pending call' and 'use check_descriptor / scan_contract for that' for danger-primitive scan. This fully covers when and when not to use the tool.

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