list_companies

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

No annotations are provided, so the description bears the full burden of disclosure. It explains important behavioral traits: account_id auto-resolution, pagination behavior (1-indexed pages, page size limit), and status filtering. This exceeds minimal requirements for a list tool.

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 well-structured with a clear first sentence and an Args block. It is concise but includes necessary details. The historical note about pagination adds context without excessive verbosity.

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 (4 optional parameters, no required params) and the presence of an output schema, the description is complete. It covers all parameters, pagination, and filtering. The only minor gap is the lack of mention of the number of results returned, but the output schema likely covers that.

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 input schema has 0% description coverage, leaving the description to explain all 4 parameters. The description does so effectively: account_id auto-resolves, per_page max 250, status values explained, page is 1-indexed and necessary for pagination. This adds significant value beyond the schema's type/default information.

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 purpose: 'List companies (client businesses) under a CallRail account.' It uses a specific verb (List) and resource (companies), and distinguishes itself from sibling list tools (e.g., list_accounts, list_calls) by specifying the resource type.

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 provides context for when to use the tool (listing companies under an account) and gives pragmatic guidance on pagination for agencies with many companies (page parameter). It does not explicitly state when not to use it or list alternatives, but the sibling tools are distinct enough that confusion is unlikely.

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