narrate

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

With no annotations provided, the description carries the full burden. It adds useful behavioral details: the narration is temporary, replaces the current one, and targets the controlled browser tab. It doesn't cover edge cases like invalid tab handling, but for a simple UI feedback tool, it provides adequate transparency.

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 three tight sentences: purpose, usage guidance, and behavior. Every sentence earns its place with no redundancy or filler, and the most important info is front-loaded.

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's simplicity, the rich schema (100% parameter coverage, output schema present), and the clear behavioral context, the description is complete enough. Return values are covered by the output schema, so no further explanation is needed.

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 schema description coverage is 100%, with each parameter already well-described (e.g., text is 'one short, user-visible sentence'). The tool description adds no additional parameter-specific meaning, so the baseline of 3 applies.

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 opens with 'Show a short, temporary narration ribbon in the controlled browser tab so the person watching understands the current workflow phase,' which specifies a clear verb, resource (narration ribbon), and purpose. This distinctly separates it from sibling tools like navigate or form_input, which perform different actions.

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 states when to use ('meaningful phase changes') and when not to ('not routine clicks or keystrokes'). However, it does not name alternative tools, so while the guidance is clear, it stops short of the 'alternatives' component required for a 5.

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