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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered structurally; the description nonetheless adds that it takes no arguments, has no side effects, and is free (a cost/rate-limit signal not present in annotations). It stops short of describing pagination or response size behavior.

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?

Dense but front-loaded: the coverage summary and per-industry breakdown come first, followed by the usage hint and the no-argument/read-only notes. The long chained sentence describing return structure is information-dense rather than padded.

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 present, the description carries the burden of explaining the return shape and does so thoroughly (summary totals, field list, per-industry counts, countries, sample sub-industries, link). Nothing an agent needs to decide to call it is missing.

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?

Zero parameters, which is the baseline-4 case, and the description reinforces this with 'Takes no arguments,' removing any ambiguity about whether filters are accepted.

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 ('Returns what the Mati Logistics supplier database covers') and then enumerates the concrete sections of the response (summary, supplier field kinds, per-industry counts). An agent can distinguish this coverage/overview tool from get_supplier or discover_suppliers without opening any 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?

Explicitly states when to use it: 'to judge whether a search here suits a request, and for phrases to search with.' This gives clear usage context, though it does not name a sibling alternative (e.g., discover_suppliers) as the contrasting action.

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