list_companies

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

No annotations are provided, so the description carries the full burden. It discloses the access scope ('the user has access to') and implies a read operation via 'List'. It does not describe pagination, ordering, or performance characteristics, but for a simple zero-parameter list tool this is acceptable though not rich. A 3 is appropriate because the description does not actively mislead and provides some behavioral scope.

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 two sentences with no filler. The first states the operation and scope, the second tells the agent exactly when to use it. Every word contributes to usability, and the structure is front-loaded.

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 that this is a zero-parameter discovery tool with no output schema, the description is complete enough. It states what the tool does and how to use it in a workflof sequence. The only minor omission is any mention of large result handling, but without annotations or schema constraints, this is not a barrier to correct invocation. Thus 4 is appropriate.

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 has zero properties, so there are no parameters to describe. The '0 params = baseline 4' rule applies. The description adds no per-value details because none are needed. It fully satisfies parameter semantics requirements.

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 lists all companies the user has access to. This is a specific verb and resource, and the scope is defined by 'the user has access to'. It distinguishes the tool from siblings like search_ledgers or get_invoice_details by focusing on the overall company list rather than a specific domain object.

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 guidance: 'Call this first to identify which company to work with'. This tells the agent exactly when to invoke the tool. It does not mention alternatives or when not to use it, but none of the sibling tools serve the same company-listing purpose, so this is adequate.

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