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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so this is clearly a safe, repeatable read. The description contributes one piece of real behavioral context: prices are a point-in-time snapshot from the check date, not live values. It does not mention ordering, pagination, or what happens when the category filter is omitted.

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 with the resource and the notable return characteristic front-loaded, then the filter. 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 single optional-parameter read tool with full annotation coverage and no output schema, the definition covers the essentials plus the non-obvious snapshot-price semantics. Only minor gaps remain, such as default behavior with no category and result ordering.

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 schema already documents the category parameter as a lowercase slug with a regex pattern. The description merely restates that category filtering exists without adding format or matching semantics beyond the schema, so the baseline 3 applies.

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 gives a specific verb plus resource ('List the products') and adds a distinguishing detail: each product carries the price it had on the day it was checked, which separates it from a bare catalog listing. It stops short of naming or contrasting with siblings such as get_product or list_product_categories, so the agent must infer the boundary itself.

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 the intended usage and signals the filter is optional, but nothing states when to choose this over get_product for a single item or list_product_categories for taxonomy work. Usage is implied rather than explained.

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