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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds valuable behavioral context: it returns all matching products with prices, images, and checkout, does not score or filter, and shows everything so the user can decide. This goes beyond what annotations alone convey.

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 longer than ideal, but every sentence carries weight. It front-loads the primary purpose, then addresses when-not-to-use, return contents, and key behavioral distinctions. No fluff, but readability could be tightened slightly.

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 4 parameters and no output schema, the description covers return values (prices, images, checkout), comparison to the recommendation sibling, and parameter usage guardrails. It does not mention pagination or sorting, but given max_results is documented, this is sufficient for a search/browse 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%, so all parameters are documented. The description adds practical nuance: query examples, a strong caveat on the category parameter ('Do not guess categories'), and clear guidance on max_results behavior ('Only set this if the user specifies a count'). This improves usability beyond raw schema.

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 clearly states the tool browses and searches the product catalog, with specific usage scenarios ('see what's available, look up specific products, browse by category, compare options'). It explicitly distinguishes itself from skincare_recommend, making the purpose unambiguous and differentiating it from siblings.

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?

The description provides explicit when-to-use guidance and an explicit exclusion: 'Do not use when the user needs personalized recommendations based on skin concerns — use skincare_recommend instead.' This leaves no ambiguity about which sibling to invoke.

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