generate_chartjs

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

No annotations are provided, so the description carries full burden. It discloses that the HTML file is written to a configurable directory (MCP_CHARTS_DIR, default ./charts) and returns the path. It also notes the behavioral quirk about pie charts using only the first series. This is adequate for behavioral expectations, though more details on overwriting or authentication would improve it.

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 only five sentences, each essential. No redundant or verbose language. It starts with the core purpose, then elaborates on supported types, output location, and usage hints. Highly efficient.

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 complexity (3 parameters, nested data object, output schema exists), the description covers the key aspects: purpose, input format, output file generation, and special behavior. It omits details like error handling or file naming, but these are reasonable gaps for a straightforward 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?

With 67% schema description coverage, the description adds value by explaining that data should be aggregated and that pie charts only use the first series. The chart_type enum is reinforced, and the title parameter is straightforward. The description supplements the schema's missing description for chart_type.

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 'Generate an interactive Chart.js HTML file from series data,' specifying the verb and resource. It distinguishes from siblings (read_metadata, interpret_column_data, run_pandas_code) by focusing on visualization output. Examples of chart types and input source are given.

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 advises to 'Feed it aggregated data — e.g. the output of a run_pandas_code group-by,' providing clear when-to-use guidance. It also notes 'Pie charts use the first series only,' which is a usage caveat. However, it does not explicitly state when not to use or mention alternatives, keeping it from a 5.

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