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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint=false), so the description only needs to add context beyond that. It does add one valuable behavioral detail, namely that the returned price is as of the last time the product was checked rather than live, but it says nothing about ordering, pagination, or whether the price snapshot can be chosen.

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?

Two short sentences, front-loaded with the action and resource, with the return-value nuance in the second clause and the filter note last. No filler and nothing redundant.

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 one-optional-parameter read tool with full annotations, only modest description detail is required, and this covers the basics. The notable gap is the "day it was checked" phrasing: no date parameter exists, so an agent cannot tell whether prices are historical snapshots or merely last-known values, or whether results are ordered in any way.

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 the single parameter is already documented as "A product category slug." The description only restates the filter's purpose, which yields no syntax or format detail beyond what the schema provides. Under full schema coverage, the baseline of 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?

States a specific verb and resource ("List the products") and adds a distinguishing detail about what is returned: the price each product had on the day it was checked. This separates it from get_product, but it never explicitly contrasts with list_product_categories or search_listings, so the differentiation is implicit rather than stated.

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?

"Filter by product category" implies that the category parameter is optional and narrows the result set, which is useful usage context. However, there is no explicit guidance on when to prefer this tool over get_product or search_listings, and no stated preconditions or exclusions.

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