Validate a MotionSpec (trust boundary)

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

Adds details beyond annotations: fail-closed behavior, returns ok=false with precise errors, and enumerates validation checks. Annotations already indicate read-only, but description enriches with specific failure mode.

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 sentences with zero wasted words. First sentence defines action and scope, second sentence gives usage hint. Front-loaded and efficient.

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?

Provides sufficient context for agent decision: validation checks performed, fail-closed outcome, and recommended usage. Lacks output schema but description hints at return format. Still complete for this simple tool.

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% and the schema itself describes the spec parameter as 'The MotionSpec JSON object'. The tool description repeats this without adding further parameter semantics, so baseline score 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?

Clearly states the tool validates a MotionSpec against schema, allow-list, bounds, and injection rules. Distinct from siblings like motion_compile (which does compilation) and motion_audit (auditing).

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?

Explicitly recommends using it 'to pre-check a spec before compiling', providing clear context and implied when-not to use (not for actual compilation).

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