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

Beyond the readOnly/idempotent annotations, the description discloses data provenance (legally mandated transparency files), update cadence (twice a day), deduplication by barcode, free-tier request limits, and the mandatory citation with checked_at. This is exactly the behavioral context annotations cannot express. No contradiction with annotations.

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 description is dense but organized: capability, return fields, data source, tier limits, downstream routing, and citation requirement. It front-loads the most important fact ('FREE, no key needed') and each sentence earns its place; only slight redundancy with the schema's limit note prevents a 5.

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 fully compensates by listing the returned fields (barcodes, size, chain count, cheapest price/chain), freshness, tier differences, and attribution obligations. An agent has everything needed to call the tool correctly and interpret results.

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 100%, so the baseline is 3. The description adds value by giving concrete Hebrew examples for query and by clarifying that limit's real-world cap is 5 on the free tier and 25 with a key, which the schema already hints at but the description makes actionable.

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?

The description opens with a specific action ('Find grocery products sold in Israeli supermarkets') and a precise query scope (Hebrew name, brand, or barcode), with concrete examples. It further distinguishes itself from siblings by pointing to get_product_prices and compare_basket as follow-up tools for per-chain pricing, so an agent can clearly separate search from price retrieval.

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?

It explicitly states when to move on to alternatives: 'Use the barcode with get_product_prices or compare_basket to show the user every chain's price and where their whole list is cheapest.' It also explains the free vs API-key tier difference, which informs whether a query will need a key for more than 5 matches.

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