list_folders

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

No annotations are provided, so the description carries full responsibility. It goes beyond a simple verb phrase by disclosing the exact return structure: 'Returns {ok, folders: [{path, files, failed_files, chunks, added_at, last_indexed_at}, ...]}.' This gives the agent a precise expectation of what the tool outputs, which is especially valuable since the input schema is empty and there is no other source of behavioral information.

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 extremely concise: two sentences, with the core action first and the return format following. Every sentence adds value, including the usage guidance, and there is no filler or redundancy.

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?

Despite having no parameters and a trivial input schema, the description covers purpose, use cases, and return format. It gives sufficient context for an agent to decide when to invoke it and what to expect, without requiring additional details like permissions or side effects since it is a read-only list operation.

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, so there is nothing to explain. Per the rubric, 0 parameters gets a baseline score of 4, and the description adds no parameter-specific semantics because none are needed.

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 registered folders with file/chunk counts and last index time. This specifically distinguishes it from sibling tools like search, add_folder, and remove_folder, making the purpose immediately obvious.

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?

Explicit usage guidance is provided: 'Use this to check what is searchable before calling search, or to find the exact registered path for remove_folder.' This directly tells the agent when to use this tool and ties it to related actions, covering both use cases and implicitly ruling out use for search or removal itself.

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