Daily health summary

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful scoping semantics (all metrics in one call, sleep attributed to the day it ended, date defaults to the user's Google Health time zone) but says nothing about response shape, missing-data behavior, or payload size. With annotations carrying the safety burden, this is adequate but not rich.

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?

Two sentences, front-loaded with the core purpose and a metric inventory, followed by a concrete usage example. No filler, no repetition of the title.

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 a single-optional-parameter read tool with no output schema, this covers purpose, scope, time-zone defaulting, and entry-point routing well. The only gap is not describing what happens for days with no data or how the metrics are aggregated, which a caller might reasonably want to know.

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 coverage is 100% and the single date parameter is fully documented in the schema, including the local-date format and today's default. The description adds only the implicit notion of a bounded single-day window, which is marginal value beyond the schema. Baseline 3 applies.

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 names a specific verb and resource (one-call overview of a single day) and enumerates exactly which metrics are returned: steps, distance, calories, active zone minutes, floors, resting heart rate, HRV, sleep, and exercise sessions. This enumeration clearly differentiates it from siblings like get_data_points or get_daily_rollup, which imply narrower raw or ranged access.

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?

It explicitly says "Start here for questions like 'how did I do today/yesterday'", giving a clear entry-point rule for day-level questions. It does not explicitly name the alternative to use for multi-day ranges or raw point queries, which is why this falls short of a 5.

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