checklist.w3c_validate_and_fix_plan.v1

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. The description doesn't state whether it modifies any files, whether it performs network requests to each URL, whether autofix actually applies changes, how many URLs it processes, or what the fix plan output looks like. Given the apply_autofix parameter suggests potential mutation, the lack of disclosure about side effects is a significant gap.

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 short sentence with minimal waste. However, it's under-specifying rather than being efficiently terse — the short length is more a function of missing critical information than disciplined conciseness. The front-loading is fine but there's essentially nothing substantial to evaluate.

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?

An output schema exists, which relieves some burden for explaining return values. However, for a tool with 5 parameters at 0% schema coverage, a generate-and-fix-plan workflow with potential autofix side effects, and six closely related sibling tools, the description is notably incomplete. It doesn't explain the relationship between validation and the fix plan, how paths vs urls interact, or what triggers autofix behavior. It's marginally acceptable for an agent that might explore the schema, but fails to deliver meaningful context.

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 0%, meaning no parameter is documented in the schema itself. The description names zero of the five parameters. The agent must infer that 'urls' is the target list, 'apply_autofix' might trigger fixes, and 'level' filters severity — but none of this is stated. With 0% coverage and 5 parameters (including a potentially dangerous apply_autofix), the description completely fails to compensate.

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 states it runs W3C validation and builds a fix plan, naming the verb (validate/fix) and resource (plan). However, it doesn't specify what distinguishes it from sibling tools like validation.w3c.validate_pages.v1, validation.w3c.autofix_safe.v1, and w3c_validate_live_urls_raw, which likely do the same fundamental W3C validation work. The phrase 'for typical landing/template issues' adds scope but isn't precise enough to differentiate from the six W3C-related sibling tools.

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?

No guidance is provided on when to use this tool versus the extensive set of sibling W3C validation tools (validate_pages, validate_and_recheck, autofix_safe, validate_urls_raw). The description says it builds a 'fix plan' which implies a planning-purpose distinction, but this is only implied, never stated explicitly. There are no exclusions or alternative tool names mentioned.

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