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

Annotations already cover readOnly, idempotent, non-destructive and closed-world, so the bar is lower; the description still adds real context: temporary signed links, bounded preview support per media type, and no spend. It omits link expiry/lifetime detail, which would matter for an agent caching a URL.

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 core action and scope in the first sentence, with no filler. The later sentence cramming Download/Edit/Animate/Upscale/Canvas actions is dense and slightly tangential to invoking this read tool.

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?

Output schema exists, so return values need no explanation, and annotations carry the safety profile. But with 2 params at 0% schema coverage, the undocumented 'lang' parameter and the phantom 'result_index' leave gaps an agent cannot resolve from structured fields.

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 description coverage is 0%, so the description must carry parameter meaning. It explains request_id only implicitly (the request whose output is read) and never mentions the 'lang' parameter or its 'ru' default at all. It also references a 'result_index' that does not exist in the schema, adding confusion rather than clarity.

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?

States a specific verb and resource: 'Read the actual account-owned output of one existing request_id.' It also scopes what is returned (bounded previews, signed links) and explicitly distinguishes itself from quoting/retrying/spending siblings. An agent can separate it from aimixer_history or aimixer_status 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?

Names when-not conditions ('Does not quote, retry or spend') and clarifies reuse without importing, which implicitly routes against aimixer_quote, aimixer_retry_quote_failed and aimixer_media_import. However, no sibling is named explicitly, so the agent must infer the alternatives from the negative list.

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