list_subdirectories

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

With no annotations, the description bears the full burden, and it does disclose the key behavioral nuance: results are as seen by Tdarr Server, not the host filesystem. It also identifies the exact API endpoint. It doesn't explicitly state that the operation is read-only or describe error behavior, though 'List' strongly implies non-mutating behavior.

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?

Two sentences with no filler. The primary action is stated first, followed by the use case and the critical path-scoping caveat. Every sentence 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 single-parameter tool with no output schema and no annotations, the description covers the action, the purpose, and the important input-semantics caveat. The agent has enough to invoke it correctly. Minor details like return format or error cases could be added but are not essential here.

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?

Schema coverage is 100% and already describes folder_path as 'visible to Tdarr Server,' so the baseline is 3. The description adds extra meaning by explaining that these are container paths, not host paths, which is not stated in the schema. This additional context helps the agent supply correct path values.

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?

Names a specific verb and resource ('List the subfolders of a path') and clarifies the Tdarr Server viewpoint, distinguishing it from filesystem-level or host-path tools. The container-vs-host path distinction further differentiates it from sibling tools like list_libraries or verify_folder_exists.

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?

Explicitly states the intended use case: 'Use it to discover the paths a library can point at.' The warning that the server sees container paths, not host paths, gives practical guidance for valid inputs. It does not name alternatives or exclusions, but this is adequate for a simple discovery tool.

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