MCP ECharts

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. While it states what the tool does (generates a chart), it lacks critical behavioral details: it doesn't mention that this is a read-only visualization tool (implied but not explicit), doesn't describe the output format (though parameters hint at image/SVG/options), and provides no information about performance, error handling, or data validation requirements.

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, well-constructed sentence that efficiently communicates the tool's purpose with a relevant example. Every word contributes to understanding what the tool does and when to use it, with no redundant or unnecessary information.

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?

Given the tool's moderate complexity (6 parameters, no output schema, no annotations), the description is adequate but incomplete. It explains the purpose well but lacks behavioral context about how the tool operates, what it returns, and error conditions. The absence of annotations means the description should compensate more with operational details, which it doesn't fully provide.

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 schema already documents all 6 parameters thoroughly. The description doesn't add any parameter-specific information beyond what's in the schema. It provides a general example of data structure but no additional syntax, constraints, or usage guidance for parameters. Baseline 3 is appropriate when the schema does all the parameter documentation work.

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 specific action ('generate a funnel chart') and purpose ('visualize the progressive reduction of data as it passes through stages'), with a concrete example ('conversion rates of users from visiting a website to completing a purchase'). It distinguishes this tool from sibling chart-generation tools by specifying the funnel chart type and its unique use case for stage-based data reduction.

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 for when to use this tool: for visualizing data reduction across stages, with a specific example (conversion funnels). However, it does not explicitly state when not to use it or name alternatives among the sibling tools (e.g., when to choose generate_bar_chart instead for non-progressive data).

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