analyze_activity_drift

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

No annotations are provided, so the description carries the burden. It clearly indicates a read/analysis operation, but doesn't disclose return format, prerequisites (e.g., HR data), or error behavior. It's not misleading, but could be more transparent about what the analysis entails beyond the metric name.

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 sentence, front-loaded with the verb and key metric, and contains no extraneous information. Perfectly concise.

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?

With only one parameter and no output schema, the description provides enough to select the tool appropriately. It explains the input (specific activity stream) and the purpose (% aerobic drift). A slightly more complete description might mention the output format or data requirements, but for a narrow analysis tool this is adequate.

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?

The schema covers activityId with a minimal 'Activity ID' description (100% coverage). The tool description adds that it's the activity stream, which gives slight context, but doesn't add meaningful detail beyond the schema. 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 specific action ('Analyzes cardiac decoupling') and the metric ('% aerobic drift'), scoped to 'a specific activity stream'. This distinguishes it from sibling analysis tools like analyze_threshold and get_hr_zones.

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 when to use it (when you need drift for a specific activity) but doesn't explicitly contrast it with alternatives or state exclusions. There's no 'when not to use' guidance, which is a minor gap given the number of sibling analysis tools.

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