set_plot_area_image

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

With no annotations, the description carries the burden of disclosing behavior. It adds useful context: local files are embedded, scaling and transparency parameters are explained, and a Desktop verification step is recommended. However, it does not mention whether setting the image overwrites an existing image, reversibility, or any side effects.

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 main verb and resource. It concisely covers the key parameters and a verification note without waste.

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 mutation tool with no annotations or output schema, it is fairly complete but lacks some context: it doesn't state what happens if the plotArea image object doesn't exist, whether the change persists in the report session, or what errors might occur. The 'Verify the render in Desktop' note is helpful but ambiguous.

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 83%, so the baseline is 3. The description adds value by clarifying imageUrlOrPath (local file embedded vs URL), explaining scaling options (Fit|Fill|Normal), and noting transparency is optional (0-100). This enriches the schema definitions.

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 'Set a chart's PLOT-AREA background image' with a specific verb and resource. It distinguishes from sibling tools like set_visual_background or set_page_background by explicitly naming the plotArea image object.

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?

No guidance on when to use this tool compared to alternatives. It does not mention exclusions or when to prefer a different image-setting tool. The only hint is the parameter explanation, which is not usage guidance.

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