oc_vitals

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

Annotations already declare readOnlyHint, destructiveHint, idempotentHint. The description adds that it requires no page scripts or package dependencies and returns specific metrics with Core Web Vitals ratings. This adds some context beyond annotations but does not significantly expand behavioral disclosure (e.g., effects on page state or limitations).

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?

Two sentences, no wasted words. Purpose is front-loaded, and key details (metrics, no dependencies) are included. Highly concise and well-structured.

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 presence of an output schema (documenting return values) and comprehensive annotations, the description is nearly complete. It lists returned metrics and Core Web Vitals ratings. Missing context might include whether the snapshot is from a specific tab (tabId) or current state, but that is implied by the parameter.

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% (tabId and timeoutMs have descriptions). The description does not add substantial meaning beyond schema – it mentions 'current page' but tabId is already clear. Slight additional context about Core Web Vitals ratings, but baseline 3 is appropriate.

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 collects a read-only Web Vitals snapshot and lists specific metrics (LCP, CLS, INP, TTFB, FCP). The verb 'Collect' and resource 'Web Vitals snapshot' are specific. However, it does not explicitly differentiate from sibling tools like performance_metrics, which may have overlapping functionality.

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 implies this is safe and lightweight (read-only, no scripts/dependencies) but provides no explicit guidance on when to use this tool versus alternatives. No when-not-to-use or comparison with other tools (e.g., performance_metrics, oc_observe) is given.

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