validate_cem

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

No annotations are provided, so the description carries the full burden. It discloses the return format (pass/fail, score, issues) and implies a read-only operation (no mention of side effects). However, it does not discuss permissions, rate limits, states dependencies (e.g., need for a loaded library), or whether the tool modifies state. Given the absence of annotations, the description provides moderate but incomplete behavioral coverage.

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 extremely concise: two sentences that directly state the purpose and output. No extraneous words, and the key information is front-loaded. Every sentence earns its place.

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 low complexity (2 parameters, 1 required, no nested objects) and no output schema, the description adequately covers the return value. However, it misses stating that a library must be loaded for validation (implied by the libraryId parameter) and what 'documentation completeness' specifically entails. The description is mostly complete but has minor gaps.

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%, with both parameters (libraryId, tagName) already described. The description adds no new information about parameters beyond what the schema provides. According to guidelines, baseline is 3 when coverage is high, which is appropriate here.

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 ('Validates'), the resource ('documentation completeness of a component in the Custom Elements Manifest'), and the outcome ('Returns a pass/fail result with a score and list of issues'). It effectively distinguishes this tool from siblings, as none of the listed siblings specifically target documentation completeness.

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 does not provide guidance on when to use this tool versus alternatives. There is no mention of prerequisites, exclusions, or scenarios where other tools (e.g., validate_component_code, validate_usage) would be more appropriate. The usage context is only implied by the tool's purpose.

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