check_token_fallbacks

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

No annotations are provided, so the description must disclose behavioral traits. It describes validation and detection of issues, implying a read-only analysis, but does not specify output format, side effects, or whether modifications occur.

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 concise with three sentences: purpose, specific detections, and usage context. It is front-loaded and contains no unnecessary words or redundancies.

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 lack of output schema and the tool's analytical nature, the description should explain what the validation result looks like (e.g., warnings list, pass/fail). It also omits that tagName and cssText are required, which is important for agent usage.

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 description coverage is 100%, so baseline is 3. The description adds context about the tool's validation purpose but does not elaborate on parameter meanings beyond the schema. No new parameter semantics are provided.

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 validates CSS for var() fallback chains and detects hardcoded colors that break theme switching, with specific examples. However, it does not explicitly differentiate from sibling tools like check_css_vars or check_dark_mode_patterns, which could overlap.

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 advises to run on any CSS referencing design tokens, providing a clear context. But it lacks explicit when-not-to-use instructions or comparisons to alternatives, leaving some ambiguity among the many sibling tools.

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