PlotMCP Server

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

No annotations are provided, so the description carries full burden. It states the tool renders lines but doesn't disclose behavioral traits like what format the output takes (image, interactive plot, etc.), whether it's idempotent, performance characteristics, or error conditions. The example shows parameter structure but doesn't explain what happens when invoked. For a rendering tool with no annotations, this is insufficient.

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 appropriately sized with two sentences and an example. The first sentence states the purpose clearly, and the second provides a helpful constraint about flat parameters. The example is well-structured and illustrates key parameters. However, the example could be more concise by omitting redundant details like 'My Plot' if not necessary.

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 has an output schema (which should describe return values), the description doesn't need to explain outputs. However, with 1 parameter (a complex object with 9 sub-properties), 0% schema description coverage, and no annotations, the description should do more to explain parameter semantics and behavioral context. The example helps but leaves many aspects uncovered for a rendering tool.

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 0%, so the description must compensate. It provides an example showing the 'series', 'title', 'width', and 'height' parameters in use, which adds meaning beyond the bare schema. However, it doesn't explain the other parameters (line_style, stroke_width, show_markers, x_label, y_label) or their effects on the plot. The example is helpful but incomplete given the 9 total parameters in the schema.

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: 'Render one or more continuous 2D lines.' It specifies the verb ('render') and resource ('2D lines'), and the 'continuous' qualifier helps distinguish it from discrete plot types like bar or scatter plots. However, it doesn't explicitly differentiate from similar siblings like plot_area (which might also render continuous lines with area fills).

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 no guidance on when to use this tool versus the eight sibling plot tools listed. It mentions 'simple flat parameters - no nested objects!' which is a technical constraint but not usage guidance. There's no mention of appropriate data types (continuous vs. categorical), visualization goals, or alternatives like plot_scatter for similar data.

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