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

Annotations already provide readOnlyHint=true, so the description doesn't need to cover safety. It adds behavioral details beyond annotations: returns status, progress, and download URL upon completion. It also implies polling behavior. However, it does not disclose potential failure modes or polling intervals.

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 a single, well-structured sentence that front-loads the primary action and packs all essential 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?

For a simple polling tool with a single parameter and no output schema, the description covers the what, the return values, and the relationship to the render tool. It lacks error-handling details, but these are not critical for a basic status check.

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?

With 0% schema description coverage, the description compensates by stating that the renderId refers to a render started with render_motion_tool, giving the parameter meaningful context. It stops short of specifying format or additional constraints, but for a single simple parameter it adds sufficient value.

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 uses the specific verb 'Poll' and identifies the resource as 'a render started with render_motion_tool', clearly distinguishing it from siblings like get_motion_tool and render_motion_tool. It also specifies the return values, making the purpose unmistakable.

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 description implicitly states when to use it: after starting a render with render_motion_tool. It does not explicitly mention alternatives or exclusions, but the sibling names and the phrasing 'Poll a render' make the usage context clear.

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