Control Media Playback

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

With no annotations provided, the description must carry the full burden of disclosing behavior. It says 'control media playback' but doesn't state what side effects occur, whether the device must be powered on, what happens on failure, or any rate limits. It also doesn't describe the return value or error behavior. This is a significant gap for a mutation tool.

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 a single, clear sentence that lists the supported actions and target scope. It is concise and front-loaded, though it could have added a bit more context without losing brevity.

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?

Given that this is a control tool with no output schema and no annotations, the description lacks important context such as error handling, device prerequisites, or whether the action applies to currently playing media across all devices. It is minimal and doesn't prepare the agent for potential edge cases.

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 input schema provides 100% coverage for both parameters, including the 'all' option for serialNumber and the action enum. The description adds no extra meaning beyond what the schema already documents. Baseline of 3 is appropriate since the schema does the heavy lifting.

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 purpose: controlling media playback with specific actions (stop, pause, play, next, previous) on a specific Echo or all devices. It is specific enough to distinguish from many siblings like alexa_speak or alexa_set_volume, though it doesn't explicitly differentiate from similar playback tools like alexa_fire_tv_control.

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?

The description provides no guidance on when to use this tool versus alternatives. It does not mention exclusions, prerequisites, or which sibling to choose for other media-related tasks. The agent is left to infer usage context from the title alone.

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