inject_css

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

The description adds significant behavioral context beyond annotations: lifetime (until navigation/reload), idempotency (re-inject replaces), and non-destructive nature (stylesheets untouched). Annotations already indicate idempotent=true and destructive=false, but description enriches with concrete details.

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?

Three concise, front-loaded sentences with no redundancy. Each sentence adds essential information: purpose, behavioral details, and scope. Excellent efficiency.

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 and the presence of detailed parameter schema, the description covers all necessary aspects: what it does, how it behaves (lifetime, idempotency), and its non-destructive nature. No missing essentials.

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 coverage is 100% with adequate descriptions for both parameters. The description does not add new parameter-level information beyond what's in the schema. The mention of 'same id' in the description implies an identifier not present in the parameters, which could cause confusion but does not directly affect parameter semantics.

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 verb 'inject' and the resource 'CSS rule into the page'. It distinguishes this tool from siblings like modify_dom or execute_js by focusing specifically on CSS injection.

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 explains persistence ('stays until next navigation') and idempotency ('re-injecting the same id replaces it'). It also clarifies it only affects rendered content, not the site's stylesheet. However, it does not explicitly state when not to use it or mention alternatives.

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