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

Annotations already cover idempotency and non-destructiveness, so the bar is lower. The description adds the useful behavioral context that widgets can override the formatting, but it does not disclose whether existing formatting is replaced or merged, or clarify how defaults apply across different widget types.

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 filler. The primary function is front-loaded, and the widget-override clarification is a valuable addition without extra verbosity.

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 9 parameters, nested objects, no output schema, and only 44% schema coverage, the description is too thin. It does not explain how to construct the formatting objects, whether the call replaces all existing formatting, or any other operational details an agent would need to invoke it correctly.

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 44%, and the description does not compensate for the undocumented nested objects (date, number, datetime, duration, percentage). It only lists the parameter names without explaining their structure or expected values, which is insufficient given the low schema coverage.

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 states a specific action ('Set') and the exact resource (default locale and number/currency/percentage/duration/date/datetime formatting for a dashboard). It also distinguishes scope from per-widget formatting by noting widgets can override these defaults, which separates it from sibling tools like set_widget_layout.

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 that this sets dashboard-level defaults and that widgets can override them, implying it should be used when configuring dashboard-wide formatting rather than individual widgets. However, it does not explicitly name alternative tools or mention when not to use it.

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