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

Annotations already convey idempotency and non-destructiveness. The description adds behavioral context beyond this: it preserves alias collision safety and makes summaries family-aware. This provides useful insight into the tool's effect on downstream data. It does not contradict annotations and adds value without over-explaining.

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 three sentences, each earning its place: purpose, usage scenario, and benefit. It is front-loaded with the action verb and immediately conveys the tool's role. No fluff or 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 tool's moderate complexity (2 params with nested array) and the absence of an output schema, the description covers the key aspects: what it does, when to use it, and its effect. It could mention what happens on successful linking or any prerequisites, but the example and context suffice for a 4.

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%, so the baseline is 3. The description enhances parameter understanding by giving real-world examples (Actavis/Cephalon as subsidiaries, Teva as parent) and explaining the purpose of linking (family-level rollups, alias collision safety). This goes beyond the schema's generic field descriptions, justifying a 4.

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 clearly states the tool's function: 'Explicitly link existing company records under a parent company for family-level rollups.' It names specific example subsidiaries (Actavis, Cephalon) and a parent (Teva), making the purpose concrete. This distinguishes it from sibling tools like fda_suggest_subsidiaries or fda_save_aliases by focusing on linking existing records rather than suggesting or aliasing.

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 gives explicit usage context: 'Use this when names like Actavis or Cephalon already belong to their own company_id and should roll up under a parent like Teva.' This tells the agent when the tool is appropriate. However, it lacks explicit when-not-to-use guidance or direct mention of alternatives, so it falls short of a perfect 5.

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