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

With no annotations, the description carries the full behavioral burden and does so well: it discloses that the claim is unsigned, that it reveals the secret on-chain, and that both legs must be funded. It also explains the chain-specific signing and return flows, including the exact Bitcoin sighash and broadcast_tx handoff.

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 front-loaded: the core action, prerequisite, secret format, and consequence come first, followed by the chain-specific return flows. Every sentence adds needed operational detail without filler.

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?

For a complex, unsigned-transaction builder with no annotations or output schema, the description covers the critical effects and return behavior across EVM, TRON, and Bitcoin. It is only incomplete on the id and leg parameter meanings, which are required for fully correct invocation.

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 explain all three required parameters. It explains that secret is a 32-byte hex preimage and implies both legs matter, but it never explains the id parameter or the meaning of the leg enum values.

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: build the unsigned claim, with the crucial effect that it reveals the secret on-chain. This clearly distinguishes it from sibling build tools such as build_fund and build_refund.

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?

It gives a clear prerequisite (both legs funded) and explains the required follow-up through broadcast_tx for Bitcoin. It does not explicitly address when to use build_claim versus build_refund or when not to use it, leaving some routing inference to the agent.

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