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

Annotations already declare a non-read-only, non-destructive, idempotent, open-world write. The description adds meaningful behavioral context beyond that: the call is a paid x402 call (HTTP 402), it settles and signs the order, and goods are paid separately on the offer's terms. This surfaces the auth/payment requirement well, though it omits error or retry semantics.

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?

Three sentences, front-loaded with the core action, and each sentence adds relevant information about the payment and settlement flow. It is slightly dense with domain jargon (x402) but still concise and structured.

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 three-param payment-bearing mutation with no output schema, the description covers purpose, the payment step, and settlement behavior. It does not explain return values or failure handling, but with annotations covering safety hints and a full-coverage schema for parameters, the remaining gaps are minor.

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 input schema has 100% description coverage, so the schema already documents all three required parameters (email, offer_id, intent_id) with hints about where each value comes from. The description adds no parameter meaning of its own, so the baseline 3 is appropriate.

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?

States a specific verb (accept) and resource (offer) plus the follow-on effect of placing the order through the Bourse. The resource name makes it naturally distinct from unrelated siblings, but the description does not explicitly name or differentiate itself from the relevant siblings (get_offers, create_order_intent), which keeps it from 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?

Usage is implied by the action itself—accept an offer to place its order—and the payment context helps an agent understand the flow. However, there is no explicit when-to-use/when-not guidance or mention of alternatives (e.g., use after get_offers), so the routing burden falls mostly on the agent.

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