generate_image

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

With no annotations provided, the description carries the full burden. It discloses authentication requirements ('Requires a you.bot API key in YOUBOT_API_KEY — NOT an OpenAI key'), cost ('$0.029 per image', '2.9 credits per call'), and output resolution ('1024px'). It doesn't mention rate limits or return format, but the core behavioral constraints are covered.

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?

Every sentence earns its place: purpose and model, capability, cost, credits, API key requirement and free key link. It's informative yet compact, with the most critical information (what it does) front-loaded before cost and authentication details.

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 tool with 100% schema coverage and no output schema, the description covers the essential invocation context: how to generate (prompt guidance), auth, cost, and output size. It doesn't specify the exact return format (URL or file), but this is a minor gap given the tool's simplicity and the sibling tools that suggest downstream usage (edit_image, check_credits).

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% — both prompt and aspect_ratio have detailed schema descriptions. The tool-level description adds little beyond the schema: it restates prompt advice (quote text) that already appears in the schema. With full schema coverage, a baseline of 3 is appropriate.

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 explicitly states 'Generate an image from a text prompt using GPT Image 2.5', which includes a specific verb and resource. It also lists capabilities (photorealism, illustration, readable text) and distinguishes from siblings like edit_image by focusing on generation rather than editing.

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: 'Good at photorealism, illustration, and rendering readable text inside the image', plus prerequisite authentication (you.bot API key, not OpenAI key) and cost. It doesn't explicitly state 'use edit_image instead when editing', but the generation vs editing distinction is strongly implied by the description and sibling tool names.

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