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

Beyond annotations, the description discloses an auth requirement (OAuth 2.1 user access token), ownership restrictions on the folder, and precise limit behavior ('more than 50 ids is refused, not truncated'). These add real context beyond the readOnly/destructive hints.

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?

Three short sentences, each carrying necessary information. Primary action is first, then edge-case behavior, then constraints. 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?

For a two-parameter mutation with no output schema, the description covers purpose, null behavior, prerequisites, id limit, and auth. The only minor omission is a statement about the response shape, but annotations and the simple operation make this acceptable.

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 includes the null-to-remove and at-most-50 semantics. The description adds one extra constraint: the folder must already exist and belong to the signed-in user, which is a meaningful validation rule for folder_id not present in the schema.

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 opens with a specific action and resource: 'File up to 50 existing transcriptions into a folder.' It also clarifies the second mode, moving them out via folder_id null, which makes the scope unmistakable. No sibling tool performs this action, so there is no confusion with alternatives.

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?

It gives a prerequisite ('folder must already exist and belong to the signed-in person') and directs the agent to list_folders for valid ids, which is concrete guidance on preparation. It doesn't explicitly name an alternative tool or say when not to use it, but no sibling overlaps with this operation, so the context is sufficient.

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