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

Annotations are sparse (only three boolean hints), so the description carries the burden and delivers substantially: it discloses that no money moves, that only a PENDING offer is created, that only one active offer can exist per product, that in-flight locks cause product_not_eligible, and the required Authorization header. This is exactly the behavioral context an agent needs beyond 'make an offer'.

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?

Four dense sentences, each earning its place: purpose, eligibility/exclusions, concurrency/error behavior, and side-effect clarity with auth requirement. The core verb is front-loaded and there is zero 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 tool with complex eligibility rules and side effects, everything needed to call it correctly is present: type of listing it applies to, seller prerequisites, exclusion cases, error behavior, pending-only semantics, the follow-up tool, and authentication. An output schema exists, so explaining return values is unnecessary.

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 the baseline is 3. The description reinforces that offered_price is a non-binding offer amount, but it doesn't add parameter-specific meaning beyond the schema — the behavioral clarification that no money moves is really transparency, not parameter semantics. The schema already explains product_id, currency_code defaulting, and the exclusiveMinimum bound.

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 ('Submits a price offer'), a precise resource ('fixed-price Resollo listing'), and actor ('authenticated buyer'). The 'never on auctions' exclusion and the distinction from the seller-side offers.respond make it unmistakable which action this performs.

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?

Explicitly states when it applies (fixed-price listings with offers enabled and a fully active Stripe Connect account) and when it does not ('never on auctions', locked/not-eligible returns product_not_eligible). Points to the follow-up alternative offers.respond, giving an agent clear routing context.

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