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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds genuinely useful behavior beyond that: 'One immediate snapshot, never loop,' which tells the agent not to poll, and 'NEVER answer null — one var2_get_*_result always matches' sets expectations on the result. It doesn't cover auth or rate limits, but the added context is substantive.

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?

Front-loaded with the purpose and densely packed with routing rules; every clause carries actionable content. Slightly repetitive, though — the phrase 'AUDIO: a song / music / track / tune' appears twice and the parenthetical examples are listy.

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?

No output schema, but the tool is a single-shot status check and the description conveys the snapshot behavior plus routing. It stops short of describing what the returned payload contains, though the inline_media schema field covers the rendering choice. Adequate for this tool's complexity.

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 50% and inline_media is already richly documented in the schema. The description compensates for the undocumented placeholder_id by clarifying it accepts 'placeholder_id or var2 link', which the schema alone does not state.

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 AUDIO: a song / music / track / tune,' and explicitly routes by media word so an agent can distinguish it from var2_get_image_result, var2_get_video_result, etc. The scope is unambiguous.

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?', 'check on it', status question with an id/link), when-not-to-use (action verbs like 'upscale', 'extend it' belong to create/modify tools), and names the paired tool var2_create_audio. Nothing is left to inference.

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