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

Goes well beyond the readOnly/openWorld annotations: it defines match_quality tiers, states which tiers return no rows, describes demand queuing (queued_for_creation, queued_product_request), and discloses the commission disclosure field on buy_url responses. That is exactly the kind of side-effect and side-channel context an agent needs.

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?

Front-loading is good – the verb and concrete examples come first – but the remaining text is a dense, unbroken block of response-shape and mode vocabulary. Most sentences earn their place, yet the lack of structure makes it harder to scan than its length alone would justify.

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 carries the burden of explaining the return shape (products[0], shelf_context, interpretation, card_specs, disclosure), which it does in detail. The omission of pagination and sorting behavior is the main remaining gap for a tool this complex.

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 coverage is only 20%, so the description must compensate, and it does thoroughly for the query parameter's semantics (mode resolution, hard vs soft constraints). However, sort, limit, and cursor are never mentioned in either schema or description, leaving three parameters unexplained.

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 ('Answer one free-text shopping query') and clarifies the query-shape modes (product, comparison, category). It never names siblings like lookup_product or browse_category, so the agent must infer the split itself, which keeps it short of 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?

Four example queries plus explicit mode triggers ('A query naming one specific product...', "'A vs B'...", 'Otherwise the category is resolved') give clear context for when each behavior applies. It offers no explicit exclusions or pointer to an alternative tool for exact-SKU or browse use cases.

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