lookup_companies

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

With no annotations provided, the description fully carries the behavioral disclosure burden. It explains cost per domain, free misses/malformed domains, and deduplication of duplicates and www variants, giving the agent a clear picture of side effects and edge-case behavior.

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 concise and front-loaded with the core purpose. Every sentence adds critical information: bulk capability, alternative usage, and cost/dedup rules. No wasted words.

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 simplicity (one parameter, no output schema), the description covers everything needed: what it does, when to use it, cost structure, and edge-case handling. It is complete without being verbose.

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?

The schema already documents the 'domains' parameter with format and maxItems. The description adds valuable nuances beyond the schema: duplicates and www variants collapse and are charged once, which is not in the schema description. This enriches the semantic meaning.

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: looking up companies behind up to 20 domains in a single call, returning a compact table. It also distinguishes itself from the sibling tool 'lookup_company' by emphasizing the bulk capability.

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?

Explicit guidance is provided: 'Prefer this over repeated lookup_company calls whenever you have several domains in hand.' It also explains the cost per domain and the handling of duplicates/www variants, helping decide when to use it.

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