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

Annotations already cover the safety profile (not read-only, idempotent, non-destructive, closed-world), so the description's job is to add beyond that. It does: the retired-product short-circuit behavior, the instruction to keep run_id private, and the clarification that max_charge is a cap rather than a consent-to-charge. These are non-obvious operational facts an agent could not infer from annotations alone.

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 short, front-loaded sentences with no filler; the core action leads and the safety caveats follow. Dense and effective, though the final two sentences are terse enough to be slightly cryptic out of context.

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?

This is a 13-parameter, paid, mutating tool with no output schema, so the description bears most of the explanatory burden. It covers the payment cap and the retired-product case but omits the successful return shape, the relationship between the several ID parameters, and any retry/idempotency-replay guidance that the replay-sensitive referral_code description hints at elsewhere.

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 54% across 13 parameters, so several fields (product_id, version, idempotency_key, quote_id, prepared_id) carry no descriptions anywhere. The description reinforces the version requirement and the meaning of the charge cap, but does nothing to disambiguate the quote_id/prepared_id/product_id flow, so it only partially compensates for the coverage gap.

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 and resource: 'Execute an available product using its version and schema.' The verb is precise and distinct from the read-oriented siblings (get_product, list_products) and the submission siblings. It stops short of naming the sibling it complements, so it stops at 4 rather than 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?

Gives one concrete usage condition — a retired product returns product_retired without work or payment — which is useful routing information. However, it never states prerequisites (a valid product_id/version pair, whether quote_id or prepared_id is expected first) or when to prefer this over get_product, leaving usage implied rather than specified.

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