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

The description adds the cost per call, which is useful behavioral context beyond the annotations. However, it does not mention the response format, any rate limits, or what happens if the payment is omitted beyond what the schema description already covers. Annotations already declare readOnly, openWorld, idempotent, and non-destructive, so the description does not need to repeat those, but more detail on the returned data would be helpful.

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 a single sentence that leads with the cost, immediately conveying the most important operational detail, followed by a clear purpose. No filler words; every element earns its place.

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 with one optional parameter and no output schema, so the description is mostly adequate. However, it does not describe what the search returns (e.g., list of agent metadata, addresses, etc.), which could leave an agent unsure of the output structure. Given the lack of an output schema, this is a notable gap.

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%, and the single parameter 'payment' already has a thorough description covering the x402 proof and the two-step call pattern. The tool description adds no additional semantic detail, so it meets the baseline for high schema coverage but does not exceed it.

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 uses a specific verb ('Search') and names a precise resource ('ERC-8004 registry') and target ('on-chain AI agents'). It clearly differentiates from generic tools, though it does not explicitly contrast with siblings like agent_research, so it stops short of a 5.

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 on when to use this tool versus alternatives. While the tool's purpose is distinct, the description never states when it should be preferred or excluded. The sibling list includes agent_research, which might overlap, but no comparison is made.

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