List clients

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

Since no annotations are provided, the description carries the burden of behavioral disclosure. It states that the operation is non-mutating (list), has no filtering ('every stored client'), and reveals the returned fields. It does not mention pagination, sorting, or authorization, but for a simple zero-parameter read-only tool this is sufficient context.

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, efficient sentence with no redundant wording. It front-loads the core action and scope, then lists the relevant output fields, so every word earns its place.

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?

For a zero-parameter tool with no output schema and no annotations, the description is complete enough for an agent to invoke it correctly. It clearly states the scope ('every stored client') and the fields that will be returned, leaving no significant gap.

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 zero parameters, so there is no parameter information that the description needs to enrich. The baseline of 4 applies because no parameter semantics are missing.

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 names a specific action and resource ('List every stored client') and specifies the returned fields (id, address, email, VAT id), so it is clear and not a tautology. It does not explicitly name or distinguish itself from sibling list tools such as contacts_list, so it falls short of full differentiation.

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?

No explicit guidance is given about when to use this tool versus alternatives, and no sibling tool is referenced. The intended usage is only implied by the action 'List' and the resource 'every stored client'.

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