STOP the duck

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

With no annotations provided, the description carries the behavioral disclosure burden. It clearly describes the action ('zero all motion intents'), immediacy, and operational guarantees. It does not detail potential side effects or return behavior, but for a stop command the core behavioral trait is well covered.

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 two purposeful sentences. The critical action is front-loaded, followed by availability guarantees and explicit when-to-call guidance. Every word 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 parameterless emergency-stop tool with no output schema, the description fully covers what it does, when to invoke it, and its availability guarantees. No additional context is needed for an agent to call this correctly.

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 tool has zero parameters, so the schema already fully covers parameter semantics. The description adds no parameter-specific details, which is appropriate since there are none. Baseline 4 applies.

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 states a specific action and resource: 'Immediately zero all motion intents.' This clearly differentiates it from siblings like duck_walk or duck_behavior by establishing duck_stop as the inverse/emergency operation.

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?

Explicit usage conditions are provided: 'if anything looks wrong, if a human asks you to stop, or if you are unsure what the robot is doing.' It also sets availability expectations ('NEVER gated, never rate-limited'), which tells the agent this tool is always safe to call in emergencies.

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