list_chart_families

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

No annotations are provided, so the description carries the burden. The 'list' verb implies a read-only operation, but the description does not explicitly state safety guarantees, caching behavior, or any side effects. It adds content details (whenToUse, sample variant) but not behavioral traits beyond the basic listing action.

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 two sentences with no wasted words. The first sentence delivers core purpose and structure, while the second provides actionable guidance. It is well-structured and front-loaded with key 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?

For a tool with no parameters and no output schema, the description is remarkably complete. It specifies the type of output (list of chart families with specific fields), mentions the count (65+), and gives a practical next-step hint (searching for CHART_VARIANT). All necessary context is covered.

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?

The tool has zero parameters, so baseline is 4. The description adds value beyond the empty schema by explaining that each family includes 'whenToUse', a sample variant, and sampleData, and provides guidance on using kind=CHART_VARIANT for published skins. This enriches understanding of the tool's output.

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 it lists Datawrapper-aligned chart families, specifies the count (65+), and notes they are mapped to StoryKit blockTypes. It differentiates from sibling tools like 'list_theme_families' and 'list_themes' by focusing on chart families. The additional note about searching for CHART_VARIANT provides specific usage context.

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 implies usage by explaining what the tool returns and hints at subsequent actions (searching for skins via kind=CHART_VARIANT). However, it lacks explicit guidance on when to use this tool versus alternatives, or when not to use it. No exclusions or context for sibling differentiation are provided.

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