Calldata diff

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds output granularity (argument-level and 32-byte-word-level differences), but says nothing about how decoding behaves without a signature or what happens on mismatched ABIs.

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 well-formed sentence that front-loads the action and tucks the use case into a parenthetical. Nothing is wasted.

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 description does characterize the return shape (per-argument and per-word diffs), which partly compensates for the absent output schema. But with 0% schema coverage on three parameters, an agent still lacks the information needed to supply 'a', 'b', and especially 'signature' 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?

Schema description coverage is 0% and the description never mentions the three parameters at all. The optional 'signature' field is especially important — whether it is required for decoding or merely a hint is left entirely unexplained.

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?

States a specific verb+resource: decode two calldata blobs and list differing arguments and 32-byte words. The dual-input 'diff' framing implicitly distinguishes it from the decode_calldata sibling, though it never names it explicitly.

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 parenthetical '(review multisig/governance payloads)' suggests the intended scenario, which is useful context. However, it gives no explicit when-to-use vs when-not guidance or alternative tools (e.g., decode_calldata for a single blob).

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