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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds valuable behavioral context beyond these: 'Deterministic, evidence-bounded and signed,' plus a 0.004 USDC cost. This enriches the agent's model of the operation without contradicting the annotations.

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 short and front-loads the action. The semicolon leading into '0.004 USDC' is slightly abrupt, and 'separating registration from ownership' is a bit cryptic, but no sentence is wasted and the core behavior is stated first.

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?

With output schema present and annotations covering safety and idempotency, the description does not need to explain return values. However, the input schema is open with minProperties=1, and the description does not clarify what properties an agent should supply (e.g., how to specify identity or evidence). For a specialized ERC-8004 tool, this leaves a meaningful 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?

The tool has 0 declared parameters, so the baseline is 4. The description does not document parameter details, but there are none in the schema to explain. The open additionalProperties=true schema means the description's references to 'identity' and 'evidence' are the only semantic clues, which is acceptable for a zero-param tool.

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 and resource: 'Bind an ERC-8004 registry identity to evidence.' This clearly identifies the tool's core function and adds a distinguishing constraint ('separating registration from ownership'). It does not explicitly contrast with sibling tools like erc8004_reputation_intelligence or onchain_evidence, so it falls 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?

The description gives no guidance on when to use this tool versus alternatives. It mentions the cost and behavioral properties but provides no selection criteria, prerequisites, or exclusions, leaving an agent to infer suitability from the name alone.

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