list_documents

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

With no annotations, the description carries the full burden, but the verb 'List' clearly signals a read-only, non-mutating operation and the qualifier 'open' scopes it to the active session. Error or empty-list behavior is not described, but the presence of an output schema covers return-value expectations.

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?

A single, front-loaded sentence with no filler words. Every word adds meaning: 'List' gives the action, 'open' gives the scope, and 'FreeCAD documents' gives the resource.

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 minimal complexity, zero parameters, and available output schema, the description is complete enough for an agent to select and call it. It could be slightly richer by naming list_objects as the alternative for inspecting document contents, but that is a small 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 tool has zero parameters and the schema documents this completely with empty properties. The baseline for a zero-parameter tool is 4, and there is nothing for the description to add about parameter semantics.

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 uses a specific action ('List') and a precise resource ('open FreeCAD documents'), which clearly distinguishes this from sibling tools like list_objects. An agent can understand the tool's job immediately without needing to inspect the schema.

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 the use case: whenever the agent needs the set of currently open FreeCAD documents. However, it does not explicitly mention alternatives or when not to use it, leaving comparison with sibling tools such as list_objects to inference.

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