Mark or unmark Apple Music tracks as Favorite one at a time, in order. Use an optional gap between tracks to give each a distinct timestamp and avoid timeouts.
Mark (or unmark) tracks as Favorite, one at a time in the given order.
gap_sec waits between tracks so each gets a distinct timestamp. Keep calls under ~40 tracks when using a gap so the call doesn't time out.
| Name | Required | Description | Default |
|---|---|---|---|
| gap_sec | No | ||
| favorite | No | ||
| track_ids | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full load and does disclose real behavioral traits: sequential application, gap_sec producing distinct timestamps, and a concrete timeout threshold (~40 tracks). It omits things like auth/permission requirements or what happens to invalid track ids, but the timeout and ordering disclosure is genuine value beyond structured fields.
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?
Three short sentences, front-loaded with the core action before the gap/timeout caveat. Slightly awkward line break before 'gap_sec waits...' but no wasted 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?
For a 3-param mutation with no annotations and no output schema, the description covers order semantics, the gap mechanism, and the timeout limit, which is most of what an agent needs to call it safely. Only the success/return behavior and parameter typing remain unaddressed.
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 for all three parameters. It explains favorite (mark/unmark), gap_sec (inter-track wait for distinct timestamps), and implies track_ids and ordering, but adds no format/type detail for the ids and never states the default polarity of the favorite flag.
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 and resource ('Mark (or unmark) tracks as Favorite') and makes the dual polarity explicit. It implicitly separates itself from the sibling favorite_playlist by scoping to tracks, but never names the sibling, so differentiation is left to inference.
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?
Gives operational guidance on how to call it (one at a time, in order, keep under ~40 tracks when using a gap), which implies usage context. It does not, however, say when to prefer this over favorite_playlist or how it relates to add_to_playlist/remove_from_playlist.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.