list_customers

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

No annotations are provided, so the description carries the burden. It discloses that results are scoped by user visibility, which is useful behavioral context. However, it omits any mention of pagination, ordering, or whether it is a read-only operation. For a simple list tool, these gaps are acceptable but prevent a higher score.

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 a single, front-loaded sentence with no filler. It states the action and the visibility constraint efficiently, perfectly sized for the tool's simplicity.

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 has no parameters and an output schema (which handles return structure), the description provides sufficient context: what it returns and for whom. It lacks any note on ordering or filtering, but for a simple list operation this is acceptable. A 4 is appropriate given the presence of an output schema and the straightforward nature of the tool.

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?

There are 0 parameters, and schema coverage is 100% (trivially). Per the guidelines, the baseline is 4 for 0-parameter tools. The description adds no parameter-specific meaning because there are none to describe.

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 states a specific verb ('List') and resource ('customers'), and adds the scoping 'visible to this user,' which clearly distinguishes it from sibling tools like list_projects or list_activities. It is unambiguous and not a tautology.

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 implies usage (when you need a list of customers) but provides no explicit when-to-use vs. alternative guidance. Sibling tools are obviously different resources, so the context is understood by name, but there is no explicit mention of exclusions or alternatives, as required for a higher score.

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