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list_sources

Retrieve all scene items from the current or specified scene in OBS Studio to manage and organize your streaming setup.

Instructions

List all sources (scene items) in a scene. Defaults to the current scene.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
scene_nameNoScene name. Omit to use the current program scene.

Implementation Reference

  • The handler logic for the 'list_sources' tool, which fetches scene items for a given or current scene.
    case "list_sources": {
      let sceneName = args.scene_name;
      if (!sceneName) {
        const { currentProgramSceneName } = await obs.call("GetSceneList");
        sceneName = currentProgramSceneName;
      }
      const { sceneItems } = await obs.call("GetSceneItemList", { sceneName });
      return ok({
        scene: sceneName,
        sources: sceneItems.map((item) => ({
          id: item.sceneItemId,
          name: item.sourceName,
          type: item.sourceType,
          kind: item.inputKind ?? null,
          visible: item.sceneItemEnabled,
        })),
      });
    }
  • The registration/definition of the 'list_sources' tool in the TOOLS array.
      name: "list_sources",
      description:
        "List all sources (scene items) in a scene. Defaults to the current scene.",
      inputSchema: {
        type: "object",
        properties: {
          scene_name: {
            type: "string",
            description: "Scene name. Omit to use the current program scene.",
          },
        },
      },
    },
Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden of behavioral disclosure. It successfully communicates the default behavior (current scene), but fails to describe the return structure, what constitutes a 'source' (media types, hierarchy), or error conditions for invalid scene names.

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

Conciseness5/5

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

The description consists of two efficient sentences with zero waste. The primary purpose is front-loaded in the first sentence, while the second sentence provides necessary default behavior context without verbosity.

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

Completeness3/5

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

For a tool with a single optional parameter and no output schema, the description is minimally viable but has clear gaps. It fails to clarify the data model relationship between scenes and sources or hint at the return value structure, which is critical given the absence of an output schema.

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

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, establishing a baseline of 3. The description states 'Defaults to the current scene,' but this merely echoes the schema's description ('Omit to use the current program scene'), adding no new semantic information about the parameter's usage or format.

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

Purpose4/5

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

The description clearly states the action ('List') and resource ('sources' defined as 'scene items'), distinguishing it from siblings like 'list_scenes' (which lists scenes) and 'list_audio_inputs' (which lists specific input types). The scope is explicit ('in a scene').

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

Usage Guidelines3/5

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

The description mentions that it 'Defaults to the current scene,' implying when to omit the parameter, but lacks explicit guidance on when to use this versus alternatives like 'list_audio_inputs' or prerequisites for specifying a scene name.

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

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