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

With no annotations, the description carries the behavioral disclosure burden. It does disclose the core behavior: EIP-191 personal_sign semantics and that a signature is returned. However, it omits important context such as the sensitivity of the private key, signature format, and potential failure modes.

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?

Two concise sentences deliver the operation, standard, inputs, and output with no filler or repetition. The most important information is front-loaded.

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 two-parameter signing tool without an output schema, the description covers the input purpose and the return value. It is minimally viable, but it lacks details an agent would benefit from: exact signature encoding, private key format requirements, and any caution around handling a secret key.

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 coverage is 100%, but the schema descriptions are generic ('Message to process', 'PrivateKey to process'). The description adds meaning by clarifying that the message is the data to sign and the privateKey is the signing key. It does not specify input formats such as hex encoding or 0x-prefix expectations.

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 states a specific verb ('Sign'), a specific resource ('a message with an Ethereum private key'), the exact scheme ('EIP-191 (personal_sign)'), and the result ('returns the signature'). This clearly distinguishes it from the many sibling crypto utilities.

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?

No guidance is provided about when to use this tool versus alternatives such as x402-eth-recover or other signing/verification tools. There are no conditions, exclusions, or references to sibling tools.

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