add_video_to_playlist

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

No annotations are provided, so the description carries the full behavioral burden, and it discloses almost nothing: no auth/ownership requirements, no note on duplicate entries, no rate-limit or quota behavior. The existence of an output schema relieves it of explaining return values, which keeps this above a 1.

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?

Very short and front-loaded with the core action in the first sentence. The 'Args:' block is somewhat redundant with the input schema but not wasteful.

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 two-required-parameter tool with an output schema, the description covers the basic contract. However, with no annotations and no permission or duplicate-handling context, an agent still lacks information about failure modes and preconditions.

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 description coverage is 0%, so the description must compensate. It adds a genuinely useful format hint for playlist_id ('starts with PL') but video_id is only restated as 'Video id to add', adding nothing beyond the schema. Partial compensation only.

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?

States a specific verb ('Add') and resource ('a video to a playlist'), which is unambiguous and clearly distinct from the sibling remove_video_from_playlist. It does not explicitly name or differentiate against siblings, but the name and description are specific enough that an agent can select it correctly.

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?

There is no when-to-use guidance, no prerequisites, and no mention of the natural alternative (remove_video_from_playlist) or related tools like create_playlist. Usage is only implied by the verb-resource phrasing.

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