get_vo2max

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

With no annotations, the description carries the burden and does disclose two useful behavioral facts: one-decimal precision and the default 90-day window. It stops short of stating read-only nature or return shape, but the rounding nuance is genuinely non-obvious context an agent could not infer from the schema.

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?

Three short sentences, all front-loaded: what it does, why it matters, and the default window. No filler or restatement of the tool name.

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?

No output schema exists, so the description should ideally sketch the returned series shape, which it only implies via 'history' and 'trend'. Otherwise complete for a two-optional-date read tool, with the default window and precision behavior explained.

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 100%, so both date parameters and their formats are already fully documented. The description only restates the 90-day default, adding no syntax or constraint detail 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?

States a specific verb and resource ('Get VO2max history') and immediately differentiates itself from siblings with the precision framing, which no other tool in the list shares. An agent can distinguish this from get_health_metrics or get_daily_overview without opening the schema.

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?

Gives a clear motivating condition — Garmin's UI rounds to whole numbers and can appear static for months, so use this to see the real trend. It doesn't name an explicit alternative or exclusion, but the when-to-use context is concrete and actionable.

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