Create a chart

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

Annotations only declare the safety profile (not read-only, non-destructive, non-idempotent); the description adds genuinely new behavior: a confirmation-token gate on the proposed choices and persistence of charts for later report building. It omits what happens on overwrite and what `file` refers to, keeping it below a 5.

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?

Dense but front-loaded: the chart-type-to-column mapping comes first, then the confirmation precondition, then persistence. Nearly every clause carries information, though the chart-type list makes it a heavy single paragraph that could be split for scanability.

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 an 11-parameter mutation tool with no output schema, the description covers the core selection and confirmation workflow well. However, `file` is required yet never explained, and `overwrite`, `bins`, and `title` have no guidance anywhere, leaving real gaps for correct invocation.

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 only 9%, so the description carries most of the burden — and it does, by mapping each chart type to its required columns (e.g. box_plot needs column + optional group_column; pie needs x_column categories with optional y_column sum). Still leaves `file`, `title`, `bins`, and `overwrite` unexplained.

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?

Opens with a specific verb+resource ('Creates a chart') and immediately enumerates the six supported chart types, making it clearly distinguishable from siblings like describe, group_summary, and build_report. An agent knows exactly what output this produces.

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?

States a clear precondition ('The user confirms the chart type and columns first') and a downstream relationship ('Charts are kept for build_report'), which tells the agent both when to call and what the result feeds into. It does not explicitly name an alternative tool for non-chart exploration, so not quite a 5.

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