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

Annotations already declare readOnlyHint=true, destructiveHint=false, so the safety profile is covered. The description adds useful return format context ('Returns a widget card with the product details, image, price, and checkout button'), going beyond annotations. It does not mention edge behaviors like both params provided, but this is a minor gap given the read-only nature.

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: the first states the tool's purpose, the second gives usage guidelines with examples, the third explains the return value. Every sentence contributes unique value, and the description is front-loaded with the core function. No redundancy or fluff.

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?

The tool is simple (2 optional params, no output schema). The schema documents parameters, annotations cover safety, and the description covers purpose, usage, return format, and exclusions. There is no missing information that an agent would need to invoke the tool correctly.

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 description coverage is 100%: 'sku' is described as 'Exact product SKU (e.g. ...)' and 'title' as 'Product title to search for (fuzzy match)'. The description merely echoes 'by SKU or title' without adding new parameter-level meaning. Since the schema already fully explains the parameters, a 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 starts with 'Get full details for a specific product by SKU or title,' which names the exact verb and resource. It distinguishes itself from sibling tools by explicitly saying 'Do not use for browsing or recommendations — use search_products or skincare_recommend.' This makes the tool's scope clear and unique.

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 provides explicit when-to-use guidance ('when the user asks about a specific product by name') with concrete query examples. It also includes when-not-to-use instructions and names the exact alternative tools, giving the agent clear decision criteria.

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