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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context: the composite payload structure, optional NIST function filtering, the data source (compliance_controls reference data), and the $0.50 USDC per call cost. It doesn't describe pagination or error behavior, but for a read-only lookup this is adequate.

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?

The description is a single dense paragraph that front-loads the use case, then lists the payload fields, the optional filter, an example, the source, and the cost. It's slightly long but every sentence carries information an agent needs. The cost disclosure is a valuable addition.

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 tool with one optional enum parameter and no output schema, the description covers the use case, payload shape, filter semantics, data source, and cost. It doesn't explain what the controls[] array contains in detail, but the example hints at implementation statuses. This is complete enough for an agent 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 description coverage is 0%, so the description must compensate. It does: it explains the nistFunction parameter's purpose (filter by NIST function from compliance_controls reference data) and gives a concrete example (MAP). The enum values are in the schema, but the description adds meaning about what filtering accomplishes.

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?

The description states a specific purpose: assessing EU AI Act compliance readiness ahead of the August 2, 2026 deadline or board AI governance briefings. It names the resource (EU AI Act coverage) and the composite payload fields, distinguishing it from siblings like get_nist_ai_rmf_requirements and get_uk_fca_coverage.

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 explicitly says when to use it (compliance readiness assessment, board briefings) and gives a concrete example of filtering by NIST function MAP. It doesn't explicitly state when not to use it or name alternatives, but the context is clear enough for an agent to select it appropriately.

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