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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false. The description adds rate limits (Free: 30/hr, Pro: 500/hr), return fields, and the concept of undefended_techniques as gaps worth flagging. This is substantial behavioral context beyond what annotations provide.

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 multi-sentence but every sentence carries distinct value: purpose, usage scenario, definitions of output fields, a pairing suggestion, rate limits, and the return structure. It is front-loaded with the core purpose and contains no filler.

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?

Covers input, output fields, usage context, rate limits, and next_calls. Since an output schema exists, the description doesn't need to explain return values in detail, but it still lists the key fields. It fully contextualizes the tool within its batch-assessment use case.

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 covers 100% of the param including maxItems, type, and an example. The main description only repeats 'list of ATT&CK T-codes' without adding new semantic detail, so it remains at the baseline 3 for high schema coverage.

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 opens with 'Batch coverage breakdown: given a list of ATT&CK T-codes, return distinct defense counts per D3FEND tactic + identify which techniques have NO D3FEND mapping' — a specific verb+resource+scope. It clearly distinguishes from sibling d3fend_defense_for_attack by emphasizing batch assessment of an entire campaign.

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?

States 'Use to assess the defensive posture of an entire attack campaign or threat model in one call' and explicitly recommends pairing with cve_search per gap, providing clear context and a complementary alternative. It doesn't explicitly exclude single-technique lookups, but the batch framing makes the usage context clear.

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