w3c_validate_pages

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. It only states the alias relationship and deprecation status. It does not describe what validation performs (e.g., W3C HTML conformance checking), return behavior, network dependencies, rate limits, or auth requirements. The deprecation warning is behaviorally relevant and useful, but beyond that, the agent learns nothing about how this tool behaves or what side effects (if any) it has. For a validation tool with zero annotations, this is a substantial 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 that conveys deprecation and alias identity in minimal words. There is zero waste. However, this is under-specification rather than genuine conciseness—the description is brief because it omits nearly all functional content rather than because it efficiently captures everything needed. I'm crediting the brevity but noting the lack of functional substance prevents a 5.

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 a validation tool with zero annotations, no behavioral detail, and an output schema present, the description should clarify what the validation covers, what the returns mean, and how the deprecated alias differs from its canonical replacement. It provides none of that. The target tool name in the description (validation.w3c.validate_pages.v1) is a sibling, which helps the agent locate the canonical implementation, but the description itself is not self-contained. For a tool meant to be invoked directly, this is incomplete.

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%, and there are only 2 parameters: pages (required, array of {url, html}) and level (enum error/warning, default error). The description adds nothing about these params. However, since both parameters have well-structured schemas (pages is self_explanatory as the HTML content to validate, and level is fully enumerated), the schema carries most of the semantic load. With only 2 params and clear enum values, the baseline-3 applies because the schema does the heavy lifting and the description doesn't need to compensate heavily.

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 says 'DEPRECATED alias for validation.w3c.validate_pages.v1.' This identifies the purpose via the alias target, but it's essentially a pointer to another tool rather than a self-contained statement of what the tool does. It tells the agent this is the deprecated alias of the v1 canonical tool, which conveys that its functionality matches that target, but it doesn't describe the actual behavior (validating HTML pages) in its own words. The naming and target-reference make the core purpose inferable, but for a deprecated alias the description arguably heightens rather than resolves confusion: the agent must look up the canonical tool to understand what this does.

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 states this is deprecated, implying the agent should prefer the canonical sibling (validation.w3c.validate_pages.v1) and not use this alias. That's a form of when-not-to-use guidance. However, it does not explicitly say 'use validation.w3c.validate_pages.v1 instead' nor explain any alternative like w3c_validate_live_urls_raw vs pages-level validation, or the validate_and_recheck/autofix siblings. For a deprecated alias, the when-to-use guidance is effectively 'when you want the old version'—but minimal practical alternative direction is missing.

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