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

Annotations are minimal (readOnlyHint=false, destructiveHint=false, idempotentHint=false), so the description carries the burden. It discloses cost per wallet, billing on retries, free empty results, filtering logic, and the ACCOUNT_REQUIRED error. This goes well beyond annotations and gives the agent a clear picture of side effects and edge cases.

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 dense but every sentence earns its place. It front-loads the core purpose, then explains filtering, cost, and usage tips in a logical order. No fluff or repetition. The structure aids comprehension despite its length.

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 covers usage, cost, filtering, pagination, and error conditions comprehensively. However, since there is no output schema, it does not describe the return format (e.g., wallet object structure). For a list tool, this is a notable omission, but the description still gives enough for an agent to call it correctly and interpret results at a high level.

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%, so the baseline is 3. The description adds value beyond the schema by explaining the .eth suffix pitfall ('stripping the suffix will find nothing') and the cost implications of pagination. It also clarifies the cursor's role in the context of billing. This extra context justifies a 4.

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: 'Find the wallets in the index attested to a Farcaster account.' It specifies the resource (wallets), the scope (attested to a Farcaster account), and adds precise filtering behavior (only wallets whose recorded sources are all attested). This distinguishes it from sibling tools like walletlink_wallets_by_x_handle, which target a different identity type.

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 provides clear usage guidance: how to pass the username (including .eth suffix), prerequisites (key belonging to an account), and pagination (omit cursor for first page). It also explains cost implications and error conditions (ACCOUNT_REQUIRED). However, it does not explicitly state when to use this tool over alternatives like walletlink_wallets_by_x_handle, though the name implies the distinction.

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