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

The description discloses that the tool returns immediately and the fetch runs in the background, and directs the agent to call get_widget_data to read results. This goes beyond the annotations (which only provide idempotentHint and openWorldHint) by adding the asynchronous behavior and retrieval pattern. No contradiction with annotations.

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 four sentences with zero fluff. It front-loads the purpose, then distinguishes from alternatives, explains the async behavior, and names the sibling for whole-report refreshes. Every sentence earns its place and is directly actionable.

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?

The tool is moderately complex (4 params, nested object, output schema). The description covers the key behavioral aspects (immediate return, background fetch, how to retrieve results) and alternatives. It doesn't describe error handling or failure modes, but those are not essential given the output schema and the fact that the fetch is background. It is sufficiently complete 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 100%, so all parameters are already documented in the schema. The description adds no new meaning to parameters like timezone or date_range beyond what the schema provides. It mentions widget_ids but only in the context of usage, not semantic enhancement, so baseline 3 is appropriate.

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 verb ('re-fetch') and resource ('specific widgets with their saved config') and clarifies that it saves results. It explicitly contrasts with update_data_widget and refresh_report, making the tool's role distinct among siblings.

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?

It explicitly says when NOT to use it: 'Configuring a widget with update_data_widget already refreshes it, so this is for re-reading without a config change.' It also points to refresh_report for whole-report refreshes and to get_widget_data for reading results, giving clear routing guidance.

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