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

Annotations already declare a safe, idempotent, read-only operation, so the burden is light; the description nonetheless adds rich behavior beyond them — affiliate disclosure on the vendor handoff, a fixed order that never uses commission, a share_url, summary_markdown, and depends_on facts for later re-checking. It also discloses a methodology rule ('documented only from vendor's own pages, never as tested by us'). Gaps remain around rate limits or pagination, but coverage is well above the annotation baseline.

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 purpose is front-loaded in the first clause, which is good, but the remainder is a dense, semicolon-chained run-on that mixes return-shape, methodology, and setup-rule detail into one paragraph. It earns most of its length yet is hard to scan.

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 and 3 low-coverage parameters, the description carries the load and does so substantially: it enumerates the return payload (per-candidate check with evidence, cheapest fitting cost, test results, unknowns, vendor handoff), the summary/share artifacts, and the setup_check interplay. Missing only clarification of 'question' and product_ids format.

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 0%, so the description must compensate. It does explain requirements.modules in detail ([{id, role}], setup semantics including per-currency costs and budget), but leaves 'question' entirely undefined and only bounds product_ids by cardinality (1-6) without format guidance. Partial compensation only.

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 clear verb ('build') and resource ('purchase file/dossier') for 1 to 6 candidate products against shared requirements, and anchors it via 'same fields as check_choice'. It references siblings (check_choice, setup_check) by name, giving partial differentiation, though it never states outright why to pick this over compare_products or check_choice.

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 through the '1 to 6 candidates' scope and the conditional rule about requirements.modules naming a setup (read setup_check for the verdict). There is no explicit when-to-use vs. when-not or a direct comparison to the sibling tools that also produce comparisons, so the agent must infer routing.

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