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

Beyond the annotations (readOnly, idempotent, openWorld), the description discloses the crucial behavioural facts: this is a live registry check that includes both active and ended cases, it costs 0.01 USDC via x402 or 5 credits of a Factline key, and the first 5 paid calls per day are free with no key needed. Cost, auth path and rate/free-tier limits are exactly the kind of context annotations cannot express.

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-loaded with the trigger and scope, then the source and returned fields, then practical constraints. Mostly dense fragments with no filler, though the opening sentence packs many comma-separated clauses that could be split for faster scanning.

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 read-only lookup with no output schema, the description covers what an agent needs: what is queried, which entity types are valid, what data comes back (court, case number, dates, administrator, claims deadline), and how billing/auth works. Nothing material 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?

Schema coverage is 100%, so parameters are already documented, but the description adds the meaningful semantic that KvK number and company name are alternative inputs ("Input: KvK number or company name"), consistent with zero required parameters. The api_key role is only hinted at here since the schema already explains it in detail, so this is a modest step above the baseline 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?

Names a specific action (check bankruptcy/suspension of payments), a specific resource (Dutch company), and even the data source (Centraal Insolventieregister / Rechtspraak) with the fields returned. It does not explicitly differentiate itself from adjacent siblings like company_health or eu_company_check, which is the only thing keeping it from a 5.

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 trigger is explicit ("Use when you need to know if a Dutch company is bankrupt or in suspension of payments") and it gives a hard scope exclusion ("Legal entities only"), which rules out individuals/PEP-style lookups. It offers no named alternatives or when-not guidance versus the other company tools, so it stops short of full routing guidance.

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