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

It adds genuine context beyond the annotations: no charge is incurred, the response includes an order id and report-coverage information, and coverage is limited for CA (federal corporations only) and US (SEC reporting companies only). However, readOnlyHint=false is counterintuitive for something described as a 'search', and the description never explains what the returned order id implies about server-side state or side effects, leaving the most important behavioral question unanswered.

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, zero waste, with the most decision-relevant fact ('Free') front-loaded and the coverage caveats consolidated at the end. Nothing is repeated from the schema unnecessarily.

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, the description correctly enumerates the returned fields and the order id, and it documents per-country coverage limits. It does not say what happens when there are zero matches, whether the order id expires, or whether results are paged, which is a modest gap for a two-parameter lookup tool.

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%, so the baseline is 3, but the description adds real meaning the schema omits: the country code list is restated and, more importantly, qualified with the CA and US coverage restrictions that materially change what a match means. It adds no format guidance for the company name beyond the schema's length bounds.

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?

Specific verb and resource: it searches an official company register for a given company name in a given country and enumerates exactly what comes back (idx, registry reference, name, address, order id, report coverage). The 'Free / Nothing is charged' framing plus enumerated return fields make it distinguishable from create_order and get_report 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?

The description makes the usage context clear: a free lookup that also tells you what a report covers and hands back an order id, which strongly implies calling it before create_order. It stops short of an explicit 'use this instead of / before X' sentence and states no exclusions beyond the country coverage list.

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