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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, and the description is consistent with a safe, non-destructive rewrite. It adds the useful detail that the rewrite targets a specific structured form, but says nothing about the shape of the returned prompt, its length, or token/rate constraints, which matters because no output schema exists.

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?

Two tight sentences: the first defines the transformation and its output, the second gives the workflow cue. No filler, and the core purpose is front-loaded.

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 two-parameter, no-output-schema preprocessor this covers purpose and sequencing adequately, and names the structural fields the rewrite produces. It is slightly thin on the mode parameter's effect on the rewrite, which is the one piece of behavior an agent must get right.

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 100%, so both parameters are already documented, and the description adds no syntax or usage detail for either. Notably it never mentions the 'mode' parameter (t2i/i2i/t2v/i2v) that determines whether the rewrite is tuned for text-to-image, image-to-image, or video, even though that choice materially affects the result.

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 ('Rewrite a rough prompt idea') and names the concrete output structure (subject, composition, style, negatives), so it is clearly not a retrieval tool like get_prompt or search_prompts. It does not, however, explicitly contrast itself with those closest-named siblings, so it falls just short of the top mark.

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?

'Use before generate_image — better input, better output' gives clear sequencing guidance and names the tool it feeds. There is no statement of when NOT to use it (e.g. when the prompt is already structured, or that it does not generate anything itself), so it is clear context without exclusions.

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