Query Vitals

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

With no annotations provided, the description carries the behavioral disclosure burden. It clearly signals a read-only query operation, explains what data is covered, and warns that freshness should be verified before drawing conclusions. It does not mention pagination or rate limits, but the presence of an output schema and the explicit query framing mitigate that 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 compact, front-loaded with the core action, and every sentence contributes either scope, metric coverage, or prerequisite guidance. It avoids fluff and remains readable despite naming many vitals categories.

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 has nine parameters, a complete input schema, and an output schema, the description provides enough additional context: it names sibling tools for prerequisites, defines the metric coverage, and warns about data freshness. It does not explicitly disambiguate from list_vitals_anomalies, but the 'timeline' framing is sufficient for correct selection.

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%, so the schema already documents all nine parameters clearly. The description adds useful context about metric_set keys via list_metric_sets and lists supported vitals categories, but it does not substantially augment individual parameter meanings beyond what the schema provides.

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 opens with a specific verb and resource: 'Query an app vitals metric set timeline.' It further clarifies scope by enumerating the covered vitals metrics and references sibling tools for keys and freshness, making it easy to distinguish this tool from list_metric_sets, get_vitals_freshness, and list_vitals_anomalies.

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 clear workflow context: call list_metric_sets to learn valid keys and check get_vitals_freshness before drawing conclusions. It does not explicitly state when not to use this tool or contrast it with alternatives like list_vitals_anomalies, so it stops short of a full when-to-use versus when-not-to-use guide.

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