Remove tracks that exist in other playlists from your base playlist, keeping only unique tracks. Specify one or more subtract playlists to filter out duplicates.
Remove tracks of B..N from A. Quota: 🟢 N GETs + DELETE or PUT.
| Name | Required | Description | Default |
|---|---|---|---|
| dry_run | No | Preview only: validate inputs and describe exactly what would change without performing it | |
| base_playlist_id | Yes | ||
| subtract_playlist_ids | Yes |
Changes observed during successful MCP inspections.
v1.26.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The quota line ('N GETs + DELETE or PUT') adds useful behavioral context about API cost and mutation method, which is not visible in schema or annotations. However, with no annotations and no output schema, the description does not disclose details like duplicate handling, reversibility, or whether only the base playlist is modified.
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 only two sentences and front-loads the operation before the quota note. The 'B..N' shorthand is compact but sacrifices some clarity; still, there is no filler or repeated schema content.
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?
The core action, operand mapping, and quota are present, but this is a mutating tool with no annotations and no output schema, so more context would help: what happens to duplicate occurrences, whether other playlist content is preserved, and any edge case behavior. It is minimally viable but leaves room for inference.
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 description assigns meaning to the two required parameters by mapping 'A' to base_playlist_id and 'B..N' to subtract_playlist_ids, which is essential since the schema gives them no descriptions. It does not specify ID formats or how duplicates are treated, but it compensates for the low 33% schema coverage on the core 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 states a specific verb ('Remove') and resource ('tracks ... from A'), making it clear this is a playlist set-subtraction operation. It also distinguishes itself from sibling set tools like playlist_intersect or playlist_union, but the shorthand 'B..N' and 'A' is not explicitly tied to the parameter names.
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 guidance on when to choose playlist_subtract over related tools such as playlist_keep_only, playlist_exclude_artists, or playlist_intersect. The description only states what the operation does, not the conditions or context in which it should be used.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.