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

Annotations declare readOnlyHint=true, but the description says the tool creates an image and may be billed at real cost or charged a fixed per-request price. This directly contradicts the read-only annotation because invoking the tool causes a paid, side-effecting action.

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 four sentences and front-loads the core action before adding billing and output details. Each sentence contributes a distinct fact, though the billing phrasing ('quoted maximum'/'quoted in the 402') is somewhat cryptic and could be tightened.

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?

The description explains billing modes, the SWOGE behavior, and that the return value is image URLs, which is useful given no output schema. However, it does not clarify what quote=true returns (a price instead of image URLs), and the read-only annotation contradiction leaves callers with inconsistent expectations about side effects.

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?

All 6 parameters are already documented in the schema, so the baseline is 3. The description adds a useful prompt nuance about SWOGE characters but does not add material meaning for count, quality, provider, quote, or aspect_ratio beyond the schema.

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 uses a specific action and resource ('Create an image') and names the two concrete providers, Grok Imagine and ChatGPT Image. This clearly distinguishes it from sibling tools like generate_video and makes the intended function unmistakable.

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 gives clear usage context by stating that the tool is for generating images and explains the two billing modes depending on API key presence. It does not explicitly list exclusions or alternatives, but the intended use case is unambiguous.

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