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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower, and the description still adds real behavior: output shape depends on whether answers are supplied, and 'unanswered questions count as gaps,' which affects how a score should be interpreted. It stops short of describing scoring weights or the readiness-level scale, hence not a 5.

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 purpose, then the two call modes in a logical order; every clause carries information. The parenthetical enumeration of all nine domains is useful for coverage awareness but makes the second sentence long, keeping it just below the tightest possible phrasing.

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, so the description must explain returns, and it does precisely: 53 questions across nine domains mapped to articles in the no-answers mode, and per-domain scores, an overall readiness level, and gaps in the answers mode. An agent has everything needed to call it correctly.

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% and the schema already documents the single answers object, its example, the yes/partial/no enum, and the unanswered-equals-gap rule. The description reinforces that same format but adds no new parameter-level detail, so baseline 3 applies.

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 ('assess how ready an organisation is for NIS2 ... or find its gaps') and goes further by naming the nine domains and the NIS2 articles the questions map to. This is clearly a readiness/gap-scoring tool, distinguishable from siblings like nis2_scope_check (applicability) and dora_checklist (different regulation).

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?

Gives explicit branching instructions: 'Call without answers to get the 53 questions' vs 'Call with answers ... to get a score per domain, an overall readiness level and the gaps.' The condition that selects each mode is stated rather than left to inference.

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