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

With no annotations, the description carries the behavioral burden. It discloses that the output is unsigned, that the bridge holds no keys and writes to no chain, and that the response value depends on specific conditions. This provides meaningful transparency about side effects and prerequisites, though it doesn't cover error handling or default response values.

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 dense sentence that front-loads the core purpose and packs in critical behavioral constraints. It avoids fluff, though it is somewhat long and could be split for readability, but every clause 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?

Given the presence of an output schema, return values are covered elsewhere. The description explains the source of the response hash, the tag format, the condition for response 100, and the signing requirements. It doesn't mention prerequisites like having a receipt already, but overall it provides enough context for a competent agent to use the tool correctly.

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 description coverage is 0%, so the description must compensate. It mentions the receipt commitment and the condition tied to replay_ok, but it doesn't explain the meaning of request_hash or response_uri. Parameter names are somewhat self-explanatory, but the description adds only partial clarity, leaving some parameters underspecified.

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 ('Build'), a precise resource ('ERC-8004 Validation Registry validationResponse args'), and the input source ('Outcome Receipt (ORC v0.1)'). It clearly distinguishes this from sibling tools like export_attestation or verify_attestation by focusing on building unsigned arguments for a validation response.

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 concrete conditions for when the response should be 100 ('only if the bridge re-verifies the receipt AND your replay succeeded') and explains the required signing step ('Sign and submit with your own signer'). It doesn't explicitly state when to use this tool vs alternatives, but the purpose is narrow enough that usage is clear.

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