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Glama

playback

Control Apple Music playback by sending play, pause, toggle, next, previous, or stop commands, and receive the updated player state in return.

Instructions

Control playback. Returns the player state afterwards.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
actionYes

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.1.0

TDQS

C2.4/5.0
Behavior2/5

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. It does disclose that player state is returned, which is a small plus, but says nothing about side effects (e.g., whether stop clears the queue), permission requirements, error behavior, or what "player state" actually contains.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short, front-loaded sentences with no filler; the tool's purpose and its return behavior come first. It is efficient, though the brevity is partly the result of under-specification rather than tight editing.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a player-control tool with no annotations and no output schema, the definition is too thin: it never describes the returned player state, session requirements, or the semantics of the destructive-ish actions (stop/next). An agent has enough to guess a call but not enough to call it confidently.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters2/5

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 the single action parameter, and it adds nothing. The enum makes the legal values self-evident, but the description never explains behavioral differences between them (e.g., toggle vs. play, or what stop does versus pause).

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose3/5

Does the description clearly state what the tool does and how it differs from similar tools?

"Control playback" states a resource and a general verb, but it does not distinguish this tool from siblings like play_track, now_playing, or set_player_options. The specific actions (play/pause/next/stop) live only in the schema enum, so the description alone reads as a vague catch-all for playback manipulation.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no guidance on when to choose this tool over play_track, play_playlist, or now_playing, nor any stated preconditions (e.g., an active player session). The agent must infer usage entirely from the name and enum values.

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