Add, remove or re-order a video in a playlist

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

Annotations provide readOnlyHint=false, destructiveHint=false, idempotentHint=false. The description adds genuinely valuable context beyond these: 'Removing an entry does NOT delete the video, only its place in the playlist' — which contextualizes the destructiveHint=false and prevents the agent from over-fearing removal. It also discloses credit cost (0 credits), the zero-based position convention, and the connected-channel requirement. No contradiction with annotations.

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 longer than average but every sentence earns its place: the itemId/videoId caveat is essential, the non-destructive removal note prevents misinterpretation, and zero-based positions affect correctness. It front-loads the core purpose and then layers in nuances logically. Could be trimmed slightly, but nothing is filler.

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 three-mode tool with 5 params and no output schema, this is remarkably complete: it covers per-action parameter requirements, the identifier semantics, the non-destructive behavior, positional convention, credits, and prerequisites. The only minor gap is that it doesn't describe what REMOVE and MOVE return, though it does mention ADD's return (itemId). Given the complexity, this is well-covered.

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 100%, but schema strings are terse ('required for add', 'required for remove and move'). The description goes well beyond the schema by explaining the critical itemId vs videoId distinction and WHY it matters (videos can appear multiple times in a playlist), how to source itemIds, and that positions are zero-based. This meaningfully reduces the chance of the agent passing the wrong identifier.

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 three specific verbs and a clear resource: 'Add a video to a playlist, remove an entry, or move an entry to a new position.' It explicitly names the three actions (add/remove/move) and the target (playlist entries), and repeatedly distinguishes entries from videos, which separates it from sibling tools like manage_youtube_playlist and manage_youtube_channel_section. No ambiguity about what this tool operates on.

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 concrete usage rules: ADD takes playlistId + videoId, REMOVE and MOVE take itemId (not videoId), with the rationale that a video can appear multiple times. It also states how to obtain itemIds via list_youtube_playlists and the prerequisite of a connected YouTube channel. It doesn't explicitly name exclusion cases ('don't use this for X'), but the action-selection guidance and workflow are clear enough.

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