emu_start

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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It adds valuable context: the operation is idempotent-ish (will reconnect/restart if running) and requires the pebble CLI. This goes beyond a basic 'what it does' statement, though it omits details like boot time or failure behavior.

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 highly concise, using three short sentences to convey the core action, idempotency, and a prerequisite. Every sentence earns its place, and the main verb is front-loaded.

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 the tool's simplicity (one optional parameter, output schema present), the description is mostly complete with the action, default, idempotency, and requirement. It could enumerate platform choices, but the output schema covers return values, so the gap is not critical.

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 has 0% description coverage, and the description only mentions 'given platform (default emery)' without explaining valid platform values or any semantics. It adds the default value but does not help the agent understand what to pass for 'platform'.

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 boots the Pebble emulator, names the resource and action, and distinguishes it from siblings like emu_stop, emu_screenshot, and pebble_build. It also notes the default platform, providing a specific scope.

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?

It provides context by mentioning idempotent behavior and a prerequisite (pebble CLI on PATH), which helps the agent understand execution conditions. However, it does not explicitly mention when to use this tool versus alternatives or exclude any cases, so guidance is implied rather than explicit.

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