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

Annotations already declare readOnlyHint=true, so safety is covered; the description adds genuinely new behavioral context — 'One immediate snapshot, never loop' tells the agent not to poll, and the inline_media note warns against re-rendering an already-seen asset. It stops short of describing the snapshot payload shape, but that is the main gap.

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 routing rule and the anti-pattern are front-loaded and every clause carries signal, but the slash-and-arrow phrasing is dense and slightly hard to parse compared with plain prose.

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?

With no output schema, the description does enough: it states the snapshot nature, the non-looping expectation, and the media-word routing needed to pick among many var2_get_*_result siblings. Only the returned status values themselves are unspecified.

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 50% (inline_media is fully documented in the schema), yet the description compensates by clarifying that placeholder_id accepts either an id or a var2 link. That is real meaning added beyond the bare schema, though it doesn't spell out format details for the id itself.

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+resource ('Status check for an IMAGE') and pins the routing key ('media word = an IMAGE → THIS tool'), letting an agent separate it from var2_get_video_result / var2_get_audio_result without opening any schema. It even names its create/modify counterparts.

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 explicit trigger phrases ('is it ready / done yet', 'where is my …' + placeholder_id or var2 link), an explicit anti-pattern (action verbs → the matching create/modify tool, NOT a status tool), and the fallback rule that one var2_get_*_result always matches. 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.