get_daily_activity

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

With no annotations provided, the description carries the full burden and does well: it states the tool is read-only, requires a specific subscription ('24/7 Activity API subscription'), and discloses empty-payload behavior for days without synced data. The schema adds even more behavioral detail about 200 responses instead of errors.

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?

Four sentences, each earning its place: the core return value, sample contents, empty-result behavior, alternative tool, subscription requirement, and safety profile. It is front-loaded with the most important information and has no filler.

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 single-parameter read-only tool with an exhaustive schema description, the description covers everything needed to select and invoke it correctly: what it returns, when to expect empty data, how to get date ranges, the subscription requirement, and its read-only nature.

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 the schema already fully documents the 'date' parameter including format, pattern, examples, and behavioral caveats. The description adds no additional parameter-specific semantics beyond mentioning that the tool covers one calendar day, which is appropriate given the schema's richness.

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 names a specific verb ('Returns'), a specific resource ('24/7 activity time-series samples for one calendar day'), and even cites the underlying API ('/247samples API'). It also lists sample contents (timestamp, steps, HR), making it clearly distinguishable from siblings like get_daily_activity_statistics and list_daily_activity.

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 explicitly says 'Use list_daily_activity to fetch a date range', giving the agent a clear alternative condition. The schema further provides concrete usage guidance: use yesterday or earlier for complete results and expect empty/partial payloads for today or future dates.

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