chartimg_v2_layout_chart_image

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

With no annotations, the description carries the burden of behavioral disclosure. It does mention that the output is base64 and that width/height are auto-clamped, which is useful. But it does not clarify whether the POST has side effects, what the response structure looks like beyond base64, or why the optional session cookies matter.

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 short and front-loads the core action, endpoint, and output format. The 'CHART-IMG v2:' prefix and the terse 'Prefer storage variant' add some noise, but overall the definition is efficient and scannable.

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 gives the endpoint, method, output format, and an input constraint, but no output schema is present and no annotations exist. It does not describe the response container, error cases, or when to supply the optional session cookies, leaving some important context for an agent to infer.

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%, so the params are already well documented in the schema. The tool description only repeats the auto-clamping behavior already present in the schema's body description, adding minimal new parameter insight.

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 operation (POST), the resource (shared layout chart image), the endpoint, and the output format (base64). The phrase 'Prefer storage variant' also distinguishes it from the sibling storage tool, so an agent can tell what this tool does and what it is not.

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 explicitly names a preference for the storage variant, which helps an agent choose between the layout chart image and layout chart storage siblings. However, it does not elaborate on when to use this image tool over other image-generation tools or what specific conditions favor it.

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