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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds context about the output (HerStack-recommended, topics with rationale), which goes beyond annotations. However, it doesn't mention error handling, pagination, or any behavioral quirks, so it remains at a baseline level beyond what annotations provide.

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 two sentences, front-loaded with the core purpose ('Call this for one specific product') followed by a concise list of return values. Every word contributes, with no fluff or repetition. This is exemplary conciseness for a tool of this simplicity.

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-parameter, read-only tool with no output schema, the description is thorough: it specifies the input semantics and enumerates all return fields (form, claim, tier, price, link, topics with rationale). It doesn't address potential 'not found' scenarios, but given the tool's simplicity and the presence of annotations, this is a minor gap. Everything an agent needs to decide whether to call it is present.

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 describes the 'sku' parameter as 'Product name or SKU, e.g. 'Chelated Magnesium''. The tool description repeats this ('by name or SKU') without adding new information. Since the schema is thorough, the description provides no additional semantic value, warranting the baseline score of 3.

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 specific verb ('Returns') and resource ('a HerStack-recommended Solgar UK product') and lists concrete output fields (form, claim, tier, price, link, topics). It clearly distinguishes itself from siblings like search_guidance by emphasizing 'one specific product', making the tool's purpose unambiguous.

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 opening 'Call this for one specific product' gives clear context for when to use this tool – when a single product is targeted. It implicitly contrasts with broader search or recommendation tools, though it doesn't explicitly name alternatives or list exclusions. The guidance is adequate but could be more explicit about when not to use it.

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