Add one or more Spotify tracks to a playlist by ID or URI, with an optional position to control where the tracks are inserted.
Add one or more tracks to a playlist
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | The Spotify ID or URI of the playlist | |
| uris | Yes | Array of Spotify track URIs to add | |
| position | No | Optional. The position to insert the tracks (zero-based) |
Changes observed during successful MCP inspections.
v0.4.4Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries full burden for behavioral disclosure. While 'add' implies a write operation, the description doesn't mention authentication requirements, rate limits, error conditions, or what happens when tracks already exist in the playlist. This leaves significant behavioral gaps.
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 a single, efficient sentence that communicates the core functionality without any wasted words. It's appropriately sized for a straightforward tool and gets directly to the point.
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 mutation tool with no annotations and no output schema, the description is insufficient. It doesn't explain what the tool returns, error conditions, authentication requirements, or how it differs from similar tools. Given the complexity of modifying Spotify playlists, more context is needed.
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?
With 100% schema description coverage, the schema already documents all three parameters thoroughly. The description mentions 'one or more tracks' which aligns with the 'uris' array parameter, but adds no additional semantic context beyond what the schema provides. This meets the baseline for high schema coverage.
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 action ('add') and resources ('one or more tracks to a playlist'), making the purpose immediately understandable. It doesn't explicitly differentiate from sibling tools like 'modify_playlist' or 'remove_tracks_from_playlist', but the verb 'add' provides reasonable distinction.
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 provides no guidance on when to use this tool versus alternatives like 'modify_playlist' or 'remove_tracks_from_playlist'. There's no mention of prerequisites, constraints, or typical use cases beyond the basic action.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.