d3fend_defense_lookup

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

Annotations already declare readOnlyHint, destructiveHint, idempotentHint, and openWorldHint. Description adds valuable behavioral context: returns 404 on missing slug, includes rate limits, and lists response fields (including attack_techniques). No contradiction.

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?

Description is concise, front-loaded with purpose, and includes all essential information (usage context, response structure, error handling, rate limits) in a few sentences without redundancy.

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?

Given the single parameter, existing annotations, and output schema (with field names listed), the description covers all necessary aspects: purpose, usage, behavior, and error scenarios, making it fully informative for agent invocation.

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 has 100% coverage for the single parameter 'defense_id'. Description adds meaning with examples (e.g., 'TokenBinding') and explains it's a CamelCase slug from the ontology URI, enriching what the schema provides.

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?

Description clearly states 'Look up a MITRE D3FEND defense technique' and distinguishes it from sibling 'd3fend_defense_search' by specifying it's for the full record and ATT&CK chain. It also identifies the tool as a lookup operation with a specific resource.

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?

Explicitly instructs to use after d3fend_defense_search for the full record and ATT&CK chain. Also mentions error handling (404) and rate limits (30/hr free, 500/hr pro), providing clear context for when and how to use the tool.

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