fill_otc_offer

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

With no annotations, the description carries the full behavioral burden. It does add real value by disclosing the return artifact (unsigned CBOR) and that the buyer's wallet must sign it, which tells the agent this is not a completed mutation. It omits irreversibility, whether the offer is consumed/locked, and any auth requirements.

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?

Two short sentences, zero padding, with the action stated first and the return contract second. 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?

With no output schema, the description correctly compensates by naming the return type (unsigned transaction CBOR) and the required follow-up signing step. What remains missing is error/precondition context — what happens if the offer is expired, already filled, or the buyer lacks funds.

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 offerId and walletAddress are already fully documented in the schema, including the bech32/addr1 format detail. The description adds no parameter-level meaning beyond that, which is the expected baseline when the schema does the work.

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?

"Accept and fill an existing OTC offer" gives a specific verb pair and resource, clearly distinct from create_otc_offer, cancel_otc_offer, and get_otc_offers. It doesn't explicitly name those siblings, but the action is unambiguous on its own.

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 phrase "an existing OTC offer" implies the precondition that the offer must already exist, and the return description implies this is a step in a sign-and-submit flow. However, it never states when to prefer this over swap_build_cbor or submit_swap, nor any prerequisites like buyer funding or offer validity.

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