send_performance

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

No annotations are provided, so the description carries the full disclosure burden. It reveals that this uses the public collection API, which hints at unauthenticated ingestion, but does not describe side effects, whether data is counted as a pageview/session, rate limits, or error behavior for an operation that sends telemetry data.

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 front-loaded sentence with no wasted words. Its brevity is efficient, but it is arguably undersized given the eight-parameter payload and missing semantic details.

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?

For an eight-parameter ingestion tool with no annotations, no output schema, and low schema description coverage, the description is too sparse. It does not explain the five Core Web Vitals fields, units, what happens on success/failure, or how this interacts with Umami analytics data.

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 only 38%, with descriptions for websiteId, hostname, and url but none for cls, fcp, inp, lcp, or ttfb. The description names 'Core Web Vitals' but adds no units, required/optional guidance, or meaning for those acronym parameters beyond what an expert might infer.

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 a specific verb and resource: 'Send Core Web Vitals.' It also names the mechanism, Umami's public collection API, which helps distinguish this from generic event or identify submission tools. However, it does not explicitly differentiate itself from siblings like send_event or send_identify.

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 gives no guidance on when to use this tool versus alternatives such as send_event, send_identify, or batch_events. It implies it is for reporting web vitals, but does not state prerequisites, exclusions, or routing conditions.

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