health_get_azm

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

No annotations are provided, so the description carries the full burden. It clearly discloses that results come from a local cache by default with auto-sync when stale, that live re-fetches from the API, and that total_minutes is an unweighted sum. This is strong behavioral transparency, though it does not cover failure modes or data availability edge cases.

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 longer than average but well-structured and entirely informative. It front-loads the core purpose, then uses clear paragraphs for metric definition, caching behavior, arguments, return values, and sibling differentiation. Every sentence contributes value.

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 complexity—caching semantics, multiple date formats, zone definitions, and sibling overlap—the description is complete. It even covers return shape and distinguishes this metric from a related tool, leaving little for an agent to guess.

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 0%, but the description fully compensates with an Args section: it defines start_date formats ("YYYY-MM-DD", "YYYY-MM", or "30d"), defaults (last 30 days), end_date default, and the meaning of live. This adds substantial meaning beyond the raw schema.

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: "Get daily Active Zone Minutes (AZM)", then clarifies it as the "headline cardio metric". It also distinguishes itself from the sibling health_get_activity by explaining the difference between AZM and active wall-clock minutes, eliminating ambiguity.

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 explicit usage context: it explains the cache/sync default behavior, how the live parameter changes fetching, and explicitly contrasts with active_minutes in health_get_activity. This helps an agent choose between related health tools with clear exclusions.

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