get_computed_styles

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 meaningful behavioral context by explaining 'browser final computed values' and that it returns a complete set of property:value pairs, which goes beyond the tool name. It does not explicitly state read-only safety, but as a getter, this is strongly implied and the description is sufficiently transparent for a simple read operation.

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 a single concise sentence that states the tool's purpose and return format without any unnecessary words. It is front-loaded and contains zero waste.

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 tool with one parameter and no output schema, the description adequately explains what is returned (complete property:value pairs for computed styles). It does not mention edge cases like multiple matching elements or error behavior, but these are not critical for a tool of this simplicity. The description is complete enough for an agent to use 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?

The schema covers 100% of the parameter (selector, described as 'CSS selector'). The description adds no additional meaning about the selector beyond implying it targets an element, which is already evident from the schema and tool name. Baseline of 3 is appropriate since the schema does the heavy lifting.

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 the tool gets all computed styles for an element with a specific verb and resource, and explicitly mentions it returns complete property:value pairs. This distinguishes it from sibling tools like get_matched_styles (matched rules) and get_layout_metrics (layout measurements).

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 no guidance on when to use this tool versus alternatives, nor any exclusions or prerequisites. It is implied that you use it when you need computed styles, but no explicit context or comparison is provided.

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