Regenerate one illustration

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

With no annotations, the description must carry behavioral disclosure. It mentions non-determinism and returning the new image in `_meta`, but fails to disclose side effects like replacing the cached image (when setId is used), permission needs, or rate limits. This is a significant gap for a mutation-like tool.

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 description is two sentences, immediately states the primary action, and includes a concise rationale for regenerating. There is no redundancy or filler.

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?

Given the tool's complexity (9 parameters, no output schema, no annotations), the description is incomplete. It leaves critical operational details unaddressed—how to select the illustration, whether the original is replaced, and the relationship between index and setId—making it insufficient for correct agent invocation.

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 only 56%, and the description only adds meaning for 'prompt' and 'aspect' by naming them as tweakable. It does not explain how to target a specific illustration via index/setId, nor clarify parameters like title, archetype, resolution. Description fails to compensate for the schema's gaps.

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 clearly states the tool's function: 'Re-render a single illustration with the same (or a tweaked) prompt and aspect.' This specific verb and resource distinguish it from siblings like create_illustrations (creating new) and get_illustration (retrieving).

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?

The description implies usage for obtaining a fresh take ('Image models are non-deterministic, so this yields a fresh take') but does not explicitly contrast with create_illustrations or get_illustration, nor provides when-not-to-use conditions. The guidance is implied, not explicit.

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