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

Annotations cover safety (readOnly, idempotent, non-destructive) but the description adds real behavioral context the annotations cannot: it returns signals only and never a buy/avoid verdict, it does not browse and uses only the domain of url, and the brand report is suppressed when includeBrand is false. Those are the non-obvious traits an agent needs.

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?

Front-loads the trigger, then the arguments, then the return shape and limits; every sentence carries information. It is dense but runs long, and the enumeration of findings partially duplicates what the output schema already exposes.

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 14-parameter, open-ended analysis tool it covers trigger, required vs optional inputs, return shape, the no-verdict limitation, the no-browsing constraint and domain exclusions. Nothing an agent needs to invoke it correctly is missing, and the output schema means return values need not be spelled out further.

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%, so the baseline is 3, and the description goes beyond it by explaining the intent of the argument set ('pass what you already read from the listing', 'each extra field sharpens the read') and clarifying that listPrice is the seller's 'was' price and that only title is required. It still omits detail on id/detail/currency, which the schema already covers.

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 ('check a product listing') and scopes it to a single listing the user is looking at, which separates it from the plural sibling check_products. It also names what the output is (trustworthiness findings), so an agent can tell what it gets back without opening the schema.

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?

Gives an explicit trigger ('when the user is looking at a specific product listing... wants to know whether it looks trustworthy') and explicit exclusions ('Not for banking, health, government or email pages'). It does not name check_products/check_brands as the alternative for bulk or brand-only checks, so routing between siblings is left partly to inference.

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