Get Garmin days

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the description's added value is the operational envelope: 7-day default window, 31-day ceiling, one-row-per-day granularity, and the fact that a `summary` block carries average/min/max per field. It omits pagination, empty-day behavior, and rate limits, keeping it short of a 5.

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?

Front-loaded with the core action and scope, then the field list, then alternatives. The metric enumeration is long but earns its place by previewing the return payload; only the repeated 31-day limit is mildly redundant with the schema.

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?

With no output schema, the description compensates by naming the returned metrics and disclosing the `summary` aggregate structure, plus the date-range constraints. It is essentially complete for calling correctly, though a note on how days with missing data are represented would close the remaining gap.

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 both date parameters are fully described with defaults, so the schema does the heavy lifting. The description largely restates the 31-day cap and the 7-day default already present in the parameter descriptions, adding little new meaning.

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 the specific verb and resource ('garmin_get_day over a date range, one compact row per day') and enumerates the metrics returned, so an agent can distinguish it from garmin_get_day, the per-metric summary tools, and garmin_search_activities without opening a 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 an explicit use case ('am I absorbing this training?' / recovery-vs-load), states the defaults (last 7 days) and the hard cap (31 days per call), and routes to named alternatives for deeper single-field drilling. When-to-use and when-not-to-use are both present.

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