Display a widget

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

The readOnlyHint annotation already declares this as read-only; the description adds that it re-renders instantly and takes a complete widget node tree, but does not disclose potential error behavior or edge cases. This matches the calibration example where annotations lower the burden and a score of 3 is appropriate.

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?

Two concise, front-loaded sentences with no redundant information. Every phrase earns its place, and the alternative tool is mentioned efficiently.

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 simple display tool with two well-documented parameters and a clear description, all necessary context is provided. The description explains purpose, usage, and data format; no output schema is needed for a display operation, and the read-only annotation covers safety.

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 baseline is 3. The description adds meaningful context beyond the schema by specifying the widget must be a 'complete widget node tree' from a previous generate_widget result and that small edits (fix label, change color) are supported, enhancing the semantic understanding.

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?

Clearly states the tool re-renders a widget JSON tree from a previous generate_widget result, with specific use cases (as-is or small edits). It distinguishes itself from siblings by explicitly saying 'For new widgets or layout changes, prefer generate_widget.'

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?

Provides explicit when-to-use context: from a previous generate_widget result, and with small edits. It also names the alternative tool for new widgets or layout changes, giving clear guidance on when not to use this tool.

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