media_controlControl OBS media sources by playing, pausing, stopping, or restarting them using the media ID or name.
Play, pause, stop, or restart a Media Source.
| Name | Required | Description | Default |
|---|---|---|---|
| action | Yes | ||
| mediaId | No | Media ID. This is the OBS input UUID returned by media_add/media_list. | |
| mediaName | No | OBS media input name. |
| Name | Required | Description | Default |
|---|---|---|---|
| ok | Yes | ||
| error | No | ||
| result | No |
Changes observed during successful MCP inspections.
v0.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations indicate a mutating operation (readOnlyHint false). The description lists actions but does not disclose side effects such as whether 'stop' resets playback position or whether 'restart' is equivalent to stop+play. Without explicit behavior notes, the agent must infer from action names.
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?
A single, front-loaded sentence listing all four actions. No fluff, maximum efficiency.
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?
Adequate for a simple tool, but it omits the requirement that either mediaId or mediaName must be provided (the schema only marks action as required). This is a functional gap; an agent might attempt to call the tool with only an action, which would fail. Output schema exists, so return values are not needed in the description.
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 descriptions cover mediaId and mediaName, and the action parameter's enum defines possible values. The tool description adds no extra parameter information, merely restating the actions. With 67% coverage and a self-explanatory enum, the description adds minimal value but is not deficient.
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 tool's function: playing, pausing, stopping, or restarting a Media Source. It uses specific action verbs and identifies the resource. While it doesn't explicitly differentiate from the sibling media_play, the broader scope is self-evident.
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?
No guidance on when to use this tool versus alternatives like media_play. It doesn't mention conditions or exclusions, leaving an agent uncertain whether media_control is preferred for a simple play operation.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.