excel_add_chart

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

The description discloses the key limitation that exceljs does not support direct chart object creation, which is not conveyed by annotations. This helps the agent set expectations. Annotations already indicate write-only (readOnlyHint=false), consistent with the description.

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 a single sentence with a parenthetical clarification, efficiently conveying the core function and limitation without redundancy.

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 covers the essential behavior and limitation, and with the schema covering parameters, it is sufficiently complete for a write tool, though it could specify the layout of written data if needed.

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 descriptions cover all 7 parameters (100% coverage), so the description does not need to add parameter details. It adds no additional explanation beyond what the schema provides, so baseline 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 '写入图表数据到指定位置' (write chart data to specified position), and clarifies that exceljs does not support direct chart creation, clearly distinguishing this from other Excel tools that create charts or write general data. The verb and resource are specific and the limitation is mentioned.

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 provides clear context by stating that after data is written, users must manually create charts in Excel, implying this tool is for preparing chart data rather than generating chart objects. It doesn't explicitly name alternatives but gives enough context for when to use it.

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