Garmin SpO2

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the description carries a lower burden. It adds the behavioral context 'when available', indicating data may not always be present, and the disclaimer 'Not medical advice'. This provides some additional transparency but not rich behavioral detail.

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?

The description is extremely concise: two sentences that state the core purpose and a necessary disclaimer. Every word is meaningful, and the most critical information (action, resource, date scope) is front-loaded.

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?

Given the tool's simplicity, a read-only SpO2 retrieval, and the presence of an output schema, the description is adequate but not thorough. It hints at data availability ('when available') but does not explain what happens if data is missing, how privacy modes affect output, or the impact of the 'raw' option. It covers the basics but leaves important operational details implicit.

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?

With schema description coverage at 67% (one parameter likely missing a description in the schema), the description adds no meaning beyond the schema. It does not mention or elaborate on any of the three parameters (date, privacy_mode, response_format), missing an opportunity to clarify usage or defaults. The baseline is 3 for high coverage, but here coverage is moderate and description contributes nothing.

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 uses a specific verb ('Get') and resource ('Garmin Pulse Ox / SpO2 data') and explicitly ties it to a date, distinguishing it from sibling tools that retrieve other health metrics like heart rate or sleep. The inclusion of 'when available' clarifies data availability constraints.

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?

The description provides no guidance on when to use this tool versus alternatives. With over 30 sibling tools for different data types (e.g., steps, heart, sleep), there is no mention of use cases, prerequisites, or when not to use SpO2. The agent must infer from context alone.

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