browser_get_computed_style

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

No annotations are provided, so the description carries the full burden. It states it is a read operation ('Get...') but does not disclose any behavioral traits such as whether the element must be visible, the performance impact, or default return format (e.g., returns all styles if no properties filter). This is minimal disclosure.

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 consists of two concise sentences with no filler. It is front-loaded with the core action and immediately follows with usage guidance. Every sentence adds value.

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 no output schema, the description should explain what the tool returns (e.g., an object of computed styles). It does not. Additionally, it does not address prerequisites (e.g., element must be in DOM) or edge cases. The complexity is moderate, but gaps remain.

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?

Input schema has 100% coverage, so baseline is 3. The description does not add any meaning beyond the schema's parameter descriptions. It mentions filtering via 'properties' in the usage hint, but this is already in the schema.

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 action ('Get the computed CSS styles') and the resource ('a specific element'). It also distinguishes the tool from siblings by noting it is for visual changes 'not reflected in the accessibility tree', providing precise context.

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 explicitly guides usage: 'Use this to verify visual changes like colors, fonts, or dimensions that are not reflected in the accessibility tree.' This gives clear context and implicit when-not-to-use, but does not name alternative tools for cases where accessibility tree suffices.

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