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

Annotations already mark the tool as read-only, idempotent, and non-destructive. The description adds genuinely useful behavioral context beyond that: results are today's shelf prices, sorted cheapest-first, include check times, and there is a caveat about summary.suspect when presenting savings.

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 sentences with no wasted words. The core result is front-loaded, followed by the optional parameter and a safety caveat; every sentence adds operational value.

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?

There is no output schema, so the description compensates by indicating key response content: per-chain prices, check times, cheapest-first ordering, and summary.suspect semantics. It does not detail the exact response shape or not-found behavior, but for a simple two-parameter read tool this is a minor gap.

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?

With 0% schema description coverage, the description carries the parameter explanation: barcode identifies the product, and include_history controls whether recorded price changes are returned. It explains the semantic role of both parameters, while the barcode format is left to the schema's pattern constraint.

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 states a specific action ('shelf price... in each Israeli supermarket chain') on a concrete resource ('one product by barcode'), sorted cheapest-first. This clearly distinguishes it from sibling tools like compare_basket, rank_chains, and search_products by its single-product, cross-chain scope.

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 clearly scopes the tool to a single barcode across tracked chains and explains when to set include_history. It does not explicitly name alternatives or state when not to use it, so the 'vs alternatives' guidance is mostly implied rather than explicit.

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