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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint. The description adds specific behavior: t=0 is empty, no credits, reveals arc/trail/burst particles, and admin enforcement. This adds value beyond annotations without contradiction.

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?

Six short sentences, front-loaded with the critical 'ADMIN ONLY' warning, and each sentence adds unique information without redundancy.

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?

The tool has 5 parameters, a nested object, no output schema, and a rich domain. The description explains the core purpose but omits what 'bind' means, what the response looks like, and the effect of type/style/duration. It's adequate for a simple preview but lacks completeness for full autonomous use.

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 only 40% (t and bind have descriptions). The description explains t's semantics (time, default 0, empty at 0) but does not clarify type, style, or duration, despite those having enums. It fails to compensate for the low schema coverage for most parameters.

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 verb ('Play/scrub') and a specific resource ('pose of a strike VFX at time t'), and clarifies it's an admin-only preview. This clearly distinguishes it from generation or project tools in the sibling list.

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 gives a clear access constraint ('ADMIN ONLY', 'Refused for non-admin keys') but does not mention when to use it over alternatives like gripforge_vfx_generate or gripforge_vfx_project_render. No explicit comparison or selection guidance.

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