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

The annotations already declare readOnlyHint=true and openWorldHint=false, but the description adds valuable behavioral context: 'no-cost,' 'does not generate images, use an LLM, or charge credits,' and 'fixed' payload. This goes beyond the annotations to clarify side-effect-free behavior and tool limitations, though it doesn't detail the return payload shape (but 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?

The description is two sentences, front-loaded with the core purpose, and every clause earns its place. It is concise without being under-specified.

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 simple tool with one optional parameter, existing output schema, and clear annotations, the description fully covers the context: what it does, when to use it, what it avoids, and its cost behavior. No additional context is needed to use it correctly.

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 parameter 'mode' has a clear description ('Which widget payload shape to return without generation') and a pattern defining allowed values. The description adds little extra meaning beyond the schema, just emphasizing 'fixed' and the debugging context. Baseline 3 is appropriate since schema does the heavy lifting.

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 purpose: 'Return a fixed, no-cost DesignForYou widget payload for ChatGPT Apps debugging.' It specifies the verb (return), resource (widget payload), and purpose (debugging). It also distinguishes itself from siblings by explicitly noting it 'does not generate images, use an LLM, or charge credits.'

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 explicit when-to-use guidance: 'Use this only to verify the template gallery/result iframe renders correctly.' It also provides exclusions by stating what it does NOT do (generate images, use an LLM, charge credits), effectively telling the agent when not to use it and implying alternatives.

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