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

Goes well beyond the annotations: discloses latency (up to a minute), the source of the drawing (recipe's own text), mandatory labeling ('Illustration, not a photo of this dish' everywhere), that it never counts as a photo, and that refusing to replace a cook's photo is a refusal rather than an error. The refusal-vs-error distinction is exactly the kind of behavior an agent cannot infer from readOnlyHint/openWorldHint/idempotentHint.

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?

Purpose is front-loaded, then usage, then behavior — a good ordering with no filler. The middle sentence is a dense compound that packs labeling, counting, and replacement rules together, costing some readability.

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 an output schema present, return values need no explanation; the description instead covers the things that matter for correct invocation: consent, latency, labeling guarantees, and the disabled-feature path. Nothing an agent needs is missing.

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 100% and the single 'slug' param is documented, so the baseline is 3; the description adds real constraint semantics by restricting it to recipes the cook owns and that lack a photo. It does not clarify what happens if the recipe already has a photo, beyond the refusal note.

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 ('draw a labeled illustration of the dish'), plus the scoping condition ('a recipe the cook owns that has no photo'). The output is distinguished from a photograph, so an agent can tell it apart from photo-related and recipe-creation siblings.

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 concrete trigger phrases ('it needs a picture', accepting the offer after create_recipe), requires asking first, and gives an explicit fallback when image generation is off (point to website photo upload). Both when-to-use and when-not-available are covered.

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