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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so safety is covered. The description adds domain-specific rules: lows come only from verified checks, 30-day vs 90-day thresholds, bundles/refurbs excluded from ranges. However, it's framed as output field documentation rather than explaining behavioral constraints on the caller.

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?

A single dense run-on sentence packed with field names and conditional rules. It is difficult to parse and front-loaded with caveats rather than the primary purpose. Information is present but not structured for quick scanning.

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?

For a read-only tool with no output schema, the description explains key return fields and their conditions, which is useful. However, it omits important contextual details such as how far back history goes, whether results are paginated, and when the caller should prefer a different tool.

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% and there is only one parameter (product_slug), documented in the schema with an example. The description adds nothing about the slug format or constraints. With a single fully documented parameter, baseline 3 is appropriate.

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 resource ('Dated prices for one product') and describes many output fields, but the core purpose is buried under field enumeration. It doesn't cleanly distinguish from sibling tools like find_best_device or compare_products that also surface pricing. The agent can infer it retrieves price history, but the verb is weak.

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?

No explicit when-to-use guidance. It never says when to call this versus check_deal, find_best_device, or compare_products, nor what timeframes suit which use case. The field descriptions imply depth but not routing.

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