get_hr_curves

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

With no annotations provided, the description carries the transparency burden. It discloses the analysis approach (finding peak HR outputs for durations) and default behavior (90 days), but does not explicitly state that it is read-only or note any side effects, leaving some behavioral ambiguity.

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 well-structured with a clear opening statement, usage context, Args section, and Returns note. It is suitably concise without unnecessary padding, though the second paragraph could be integrated more tightly.

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 simplicity and the presence of an output schema, the description covers the essential context: purpose, parameters, and return type. It does not over-explain, and there are no obvious missing prerequisites or caveats for a read-only analysis tool.

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 already describes both parameters, but the description adds value by explaining that days_back overrides time_period, providing exact time_period shorthand mappings (week=7, month=30, year=365, all), and noting the default (90 days). This goes beyond the schema's basic field descriptions.

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 'Get heart rate curve data showing best efforts for various durations' with a specific verb and resource. It explains that it analyzes HR data to find peak outputs for different time durations, distinguishing it from related siblings like get_power_curves and get_pace_curves.

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 provides context on when to use the tool ('tracking cardiovascular fitness improvements and identifying HR zones'), giving clear user intent. However, it does not explicitly name alternatives or exclusions, so it lacks the strongest form of guidance.

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