Get daily steps (date range)

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile needs no restating. The description adds real behavioral context beyond them: the 28-day cap that forces chunking and the per-day result granularity. It stops short of noting pagination, auth requirements, or data freshness/rate limits, which would be needed for 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?

A single tightly-packed sentence that front-loads purpose, then the per-day/unit detail, then the constraint and alternative. No wasted clauses, though the density makes it slightly harder to scan than two short sentences would be.

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, and the description compensates by naming the returned fields (calendarDate, totalSteps, totalDistance in meters, stepGoal). Combined with the range limit and sibling routing, an agent has everything needed to call this correctly without trial and error.

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%: both startDate and endDate already document inclusive endpoints, the YYYY-MM-DD pattern, local-calendar semantics, and the 28-day span limit. The description's range guidance largely echoes the schema's endDate text, adding little parameter meaning beyond it — 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+resource ('Get daily step totals') with explicit granularity ('one entry per day'), enumerated return fields, and a named sibling it differs from. An agent can distinguish it from garmin_get_daily_summaries without inspecting either 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 operational rule ('Maximum range: 28 days per request; split longer periods') and a concrete routed alternative with its own limit ('garmin_get_daily_summaries (up to 365 days), which also includes steps'). The condition that selects the sibling is stated, not implied.

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