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

With no annotations, the description carries the full burden and does well: it names the data source and cadence ('ONRC monthly open-data snapshot', implying possible staleness), discloses the per-call cost (2 credits) and the no-charge condition when the CUI is not found, and notes that registry status is decoded. It omits any auth/permission requirements, but cost and freshness disclosure are the operationally important traits here.

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?

One dense sentence front-loads the resource and source, followed by a short cost sentence; nothing is boilerplate. It is somewhat list-heavy, but every enumerated field maps to real return content in the absence of an output schema, so the length is largely earned.

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?

There is no output schema and no annotations, so the description must cover both returns and behavior — it enumerates the returned fields and discloses cost/source, which is close to sufficient for a single-parameter read tool. It leaves open whether data is stale between monthly snapshots and what happens on partial matches, minor gaps.

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% and the single CUI parameter is fully documented in the schema with an example format. The description adds only the phrase 'by CUI', which is already implied by the parameter; by the stated rubric this is 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?

States a specific resource (Romanian company trade-register data by CUI) and enumerates the returned content (registration number, EUID, legal form, registry status, CAEN codes, legal representatives), which distinguishes it from get_company_financials, get_company_court_cases and get_company_risk_report. It never explicitly contrasts itself with lookup_company, which likely also keys on CUI, so the boundary is inferable but not stated.

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?

Usage is only implied: the cost note ('Costs 2 credits; not billed if the CUI is not found') gives the agent a spend decision, but there is no explicit when-to-use, when-not-to-use, or named alternative among the many company-oriented siblings. An agent must infer that this is the tool for ONRC registry details rather than the general lookup.

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