get_daily_summary

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is lower. The description adds genuine behavioral value with 'where available', signaling that fields may be absent rather than guaranteed, but it says nothing about missing-data handling, source merging outcomes, or cost/latency.

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 verb first and the metric list following, no filler. The enumeration is long but each item earns its place by telling the agent exactly which data points come back.

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's metric enumeration usefully compensates by describing the return surface, and annotations cover safety. The remaining gap is modest: it doesn't explain what a 'where available' miss looks like or how cross-source conflicts surface, but the tool is otherwise well-covered.

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 date format, source enum, deduplicate, and source_priority are all already documented in the schema. The description adds no extra meaning about how these parameters affect the returned metrics, so the 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 ('Read') and a concrete resource (daily Fitbit metrics) and enumerates the exact metrics returned, so the agent knows precisely what it gets. However, it never distinguishes itself from close siblings such as get_health_snapshot, get_activity_summary, get_sleep_summary, or get_metrics, leaving overlap unresolved.

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 phrase 'in one call' hints at aggregation convenience, but there is no explicit when-to-use guidance, no when-not-to-use, and no named alternative among the 16 siblings. The agent must infer that this is the broad single-day rollup versus the more focused siblings.

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