Stop

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

Annotations already signal mutability (readOnlyHint=false), idempotency (idempotentHint=true), and non-destructiveness. The description adds a useful behavioral detail—all velocity intents are zeroed and the duck stands—but does not discuss side effects like interactions with duck_trick or state persistence.

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?

A single, front-loaded sentence immediately conveys the core effect and an accessible metaphor. There is no filler or redundant restatement of the title.

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 command with an output schema and simple behavior, the description captures everything an agent needs: it knows the call stops the duck and stands it. No prerequisites or additional context are required.

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 takes zero parameters, so there are no parameter semantics to clarify; the baseline of 4 for a parameterless tool applies. The description imposes no hidden arguments or prerequisites.

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 names a precise action—'Zero all velocity intents'—and adds an observable effect ('the duck stops walking and stands'). This clearly distinguishes it from movement-producing siblings like duck_drive and duck_push.

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 intended use is implicit from the action description: call this to halt the duck. However, it does not explicitly state when to use this tool over duck_reset, duck_drive, or other siblings, and no alternative is named.

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