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

With no annotations, the description carries the full burden and does so well. It discloses that the tool validates lender identity and maturity, warns rather than asserts when chain state may be stale, returns only an unsigned blueprint, and does not hold keys or broadcast transactions. This gives the agent an accurate model of the tool's side effects and limitations.

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 compact and front-loaded with the core purpose. The third paragraph repeats the idea of an unsigned transaction blueprint from the first paragraph, creating mild redundancy, but the overall structure is efficient and readable.

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 no output schema, the description covers the essential behavior: validation, chain-state handling, return of an unsigned blueprint, and user responsibility for signing/broadcasting. It could be slightly more explicit about the exact output shape, but for a calldata-preparation tool the description is sufficiently complete.

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 100%, so each parameter is already documented in the schema. The description reinforces the role of lender_address ('must match the loan's lender') and loan_id ('defaulted loan'), but does not add semantic detail beyond what the schema provides.

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 action ('Builds an unsigned transaction blueprint'), a specific resource ('collateral on a defaulted Gavel loan'), and a clear actor ('a lender'). This distinguishes it from sibling calldata-preparation tools such as prepare_repay_loan_calldata or prepare_claim_refund_calldata.

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 clear context for when to use it: the caller is the lender and the loan has defaulted after maturity. It does not explicitly list alternatives or exclusions, but the use case is unambiguous enough that an agent can select this tool correctly without further guidance.

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