Pulse Ox

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the description only needs to add value beyond that. It contributes the conditional-presence trait of altitude acclimation, but says nothing about empty results, units, or data latency for a same-day read.

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 front-loaded sentence with the resource first and the qualifier second; no filler, no restatement of the title.

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?

For a two-parameter, zero-required read tool with no output schema, the description plus the rich schema covers what an agent needs to invoke it. A minor gap is the absence of any note on empty/no-data responses or units, which would matter for interpreting results.

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 parameters (date, include_series) are already fully documented, including the default-to-today behavior and the count/min/max/avg aggregation for long series. The description adds only the 'one day' single-date constraint, so 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?

Names the exact resource (blood oxygen / SpO2), the temporal scope (one day), and an additional field dimension (altitude acclimation). That is enough for an agent to distinguish it from the metric-named siblings, though it never explicitly contrasts with them (e.g. get_heart_rate, get_hrv).

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?

Usage is only implied: 'for one day' scopes the call, and 'where the watch reports it' hints that altitude data is conditionally present. There is no explicit when-to-use vs. sibling guidance, no statement of what to do when the device lacks SpO2, and no note about whether data is unavailable for future dates.

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