switch_device

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

With no annotations provided, the description carries the disclosure burden. It clearly states this is a pure handoff with no content arguments and even discloses quota cost (1 read + 1 write). It does not detail failure behavior or side effects on the old device, but the core behavioral traits are transparent.

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?

Two dense sentences deliver the action, the selection mechanism, the distinction from siblings, and quota information. The most decision-relevant details are front-loaded, and every clause earns its place.

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 moderately complex tool with no annotations and no output schema, the description covers purpose, alternatives, and cost. It could add failure behavior or a pointer to device discovery, but the essential selection and invocation context is present.

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 coverage is 100%, so the schema already documents all parameters. The description adds useful framing around device_name ('fuzzy name or sidecar label') and reinforces 'no content args', but does not meaningfully explain play, dry_run, or response_format beyond their existing schema descriptions.

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 uses a specific verb and resource: 'Transfer playback to a device', and adds a clear selection mechanism ('fuzzy name or sidecar label'). It explicitly contrasts with play_on (plays content) and handoff (position-preserving id-only), which makes the tool's role unmistakable.

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 names two siblings and explains the key differences: play_on plays content, while handoff is id-only and position-preserving. It does not mention the sibling transfer_playback, which could plausibly overlap, so the routing guidance is strong but not exhaustive.

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