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

Annotations only declare readOnlyHint=true; the description adds a real behavioral constraint beyond that: 'One immediate snapshot, never loop,' which tells the agent not to poll. It also asserts a fallback rule ('NEVER answer null'). It stops short of describing what the snapshot contains, but the non-looping guidance is genuinely additive.

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?

Purpose and the routing rule are front-loaded, which is good, but the body is a dense run-on of quoted user phrases, arrows, and a repeated example that restates the 'is it ready' case already covered earlier. The signal is present but padded.

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 single-parameter read-only status tool with no output schema and annotations covering the safety profile, the description covers routing, exclusions, and the non-polling expectation. It omits any hint of what the returned status values look like, which is the only notable gap.

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 0% and the single param is undocumented in the schema, so the description must carry it. It does convey that the parameter accepts a placeholder_id or a var2 link, and shows the placeholder form in an example, but it never states the expected string format or whether a link is parsed differently.

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?

Starts with a specific verb+resource: 'Status check for a 3D MODEL / mesh / glb', and explicitly carves itself out from the sibling get_*_result tools by the 'media word' rule. An agent can distinguish it from var2_get_image_result or var2_get_video_result without opening any schema.

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?

Gives explicit when-to-use ('Is it ready / done yet?' with an id/link), when-not-to-use (action verbs like 'animate it'/'upscale' route to create/modify tools, NOT status tools), and the selection rule among sibling status tools ('pick by MEDIA WORD'). It even supplies a worked example.

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