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

With no annotations, the description carries the full burden and does disclose the shape of the output (source, exact call, return volume, fallback), which is more than most. It omits the safety/permission profile, error or no-match behavior, rate limits, and the fact that the full-tier response surfaces paid sellers - context an agent would want before invoking.

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 content is compressed into two long sentences whose opening ('Where to go for a job') is vague and whose middle is padded with sales language ('before you spend tokens on trial and error', 'the paid sellers we rate'). The actionable part - query examples and the detail mode - is buried after the pitch rather than front-loaded.

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 no output schema and no annotations, the description does enough to convey what comes back (a routed source, its call, its size, a fallback, and optionally paid sellers), but it leaves unstated what happens on no match, whether results are cached or fresh, and any authentication or licensing constraints on the returned sources.

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 already 100%, so the baseline is 3, but the description adds genuinely new information by giving example values for the required 'q' parameter that clarify the expected phrasing and granularity. The optional 'country' parameter is not addressed in the description at all, keeping this below a 5.

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 recognizable purpose: given a plain-language data need, return the best tested free official source with its call pattern and expected volume, plus a fallback. However, it frames this in marketing prose ('before you spend tokens on trial and error') rather than a crisp verb+resource statement, and it never distinguishes itself from the seller-oriented siblings (search_sellers, check_seller, sellers_on_domain).

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?

Concrete example queries ('UK company directors', 'Apple revenue', 'EU gas storage') implicitly tell the agent what kind of request this tool is for, and the detail=full note indicates a second mode. But there is no explicit when-to-use/when-not guidance and no pointer to any alternative sibling tool when this router is the wrong choice.

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