web3_challenge

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

Beyond annotations (readOnlyHint=false, etc.), the description adds behavioral context: the tool generates a challenge message that must be signed via personal_sign (EIP-191) and then used in web3_signup. It clarifies that no browser or email is needed, which aids understanding of the interaction pattern.

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 long, front-loaded with the core purpose, and includes essential usage context. Every sentence adds value without redundancy.

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 tool is simple (one parameter) and has an output schema, so the description is largely complete. It could optionally mention challenge expiration or rate limits, but the current description is sufficient for correct usage.

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% description coverage for the single 'address' parameter with a clear example. The description does not add further meaning to the parameter beyond the schema, so a baseline score of 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 'Get a SIWE (Sign-In with Ethereum) challenge message for a wallet address,' specifying the verb (Get) and resource (SIWE challenge). It distinguishes itself from sibling tools like web3_signup by identifying it as the first step in the API key creation flow.

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 explains when to use the tool: 'first step to create a free API key using only a wallet — no browser or email required.' It also instructs that the returned message must be signed and submitted to web3_signup, providing a clear usage path. No alternatives are mentioned, but the context is sufficient.

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