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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals a useful limit (max 50) and states 'Free,' but does not describe side effects, error behavior, idempotency, permissions, or what happens if the folder does not exist or videos are already in the folder. This lack of transparency is a significant gap for a mutation tool.

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, using only two short sentences. It front-loads the core purpose and includes a key limit. However, the inclusion of 'Free' is vague and arguably filler, and the description could be better structured to separate the primary action from the limit and cost. Still, it is efficient and free of unnecessary words.

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 simple add-to-folder operation, the description provides the essential purpose and a limit, but it lacks details about return values, error handling, and behavioral nuances. The schema covers parameters, but there is no output schema or annotations to fill gaps. The tool is simple enough that this description is minimally viable, but it leaves out context that would help an agent handle edge cases.

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 provides 100% coverage with descriptions for both parameters (folder_id: 'Folder UUID', video_ids: 'Video UUIDs to add'), so the baseline is 3. The description itself adds minimal parameter semantics beyond the schema, only implying the operation's effect. No additional format or constraint details are provided, but the schema adequately covers the parameters.

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's function with a specific verb and resource: 'Add videos to a folder.' It also includes a critical constraint (max 50) and cost indication (Free). This distinguishes it from the sibling tool add_accounts_to_folder, which operates on accounts rather than videos.

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 gives no explicit guidance on when to use this tool versus alternatives. While the purpose is obvious, there is no mention of prerequisites, exclusions, or alternative tools for different scenarios. For example, it does not clarify whether this tool should be used over creating a folder and then adding videos, or how it differs from bulk_track_videos.

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