get_body_battery

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, and the description merely repeats 'read-only' rather than adding anything. It does not state rate limits, whether historical ranges are capped, or how missing days are represented, which are the kinds of things annotations do not cover.

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 purpose, but the 'YYYY-MM-DD' format is stated three times across them, and the parenthetical repeats the format a fourth time. That redundancy wastes space and pushes out information the definition actually needs.

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?

An output schema exists, so return values need not be explained, and the description covers the resource, the provider, and the date format. The one material omission is the optionality and default behavior of enddate, which leaves an agent guessing at single-day versus range semantics.

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%, so the description must carry the load, and it does supply the date format 'YYYY-MM-DD' for both startdate and enddate, which the schema itself lacks. However, it never says that enddate is optional or what happens when it is omitted (the schema shows default null), so a key semantic gap remains.

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?

States a specific verb and resource: 'Return body battery values by day', naming the Garmin metric and the granularity. It does not distinguish itself from the closely related sibling get_body_battery_events, so it stops short of a 5.

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?

No when-to-use, when-not-to-use, or alternative routing is given, even though the sibling list contains get_body_battery_events and many other daily-metric tools (get_daily_stress_stats, get_sleep_data) that an agent could easily confuse it with. The only contextual clue is the parenthetical 'Garmin Connect, read-only.'

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