explain_styles

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

No annotations provided, so description carries full burden. It discloses output content (winner, losers, reasons, blast radius, scoped selector) and implies read-only diagnostic nature. Does not explicitly state 'non-destructive', but context makes it clear. Could be more explicit about read-only behavior.

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?

Description is verbose (about 150 words) with some redundancy (e.g., repeated mention of winners and losers). The front-loaded bold phrase 'The core WHY' is effective, but overall could be more concise. Structure is good with bullet-like points but still longer than ideal.

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 complexity (5 params, no output schema, no annotations), the description covers key aspects: what the tool returns (verdict, reasons, blast radius, scoped selector) and how to use parameters. It lacks exact output format but is sufficient for correct invocation. Could be more complete for detailed output expectations.

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 has 100% coverage with descriptions, and description adds value by explaining the 'property' parameter with an example ('margin-bottom') and context for other parameters (x/y as viewport, uid from prior snapshot). It also notes the optional property to focus, enhancing schema meaning.

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 explains the CSS cascade verdict per property, naming winners and losers with reasons. It uses specific verbs like 'explain' and 'diagnose', and distinguishes from siblings by comparing to source search and style_diff. The resource is explicitly the CSS cascade.

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 scenarios (wrong style, won't apply, overriding rule) and when-not (prefer over grepping source). It gives examples of symptoms and recommends diagnosing before editing. However, it doesn't explicitly contrast with all sibling tools like explain_animations or style_diff, but the guidance is strong enough.

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