generate_daily_digest

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

No annotations are provided, so the description carries the full burden. It discloses that this is a write operation updating a sidecar file and a history file, names the sidecar path and env var, explains the CTL/ATL/TSB computation, rolling baselines, party-night bucket, and subscription fallback — far beyond what the schema provides.

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 long but almost every sentence carries distinguishing information — side effects, state persistence, calculus, subscription requirements. It front-loads the core purpose and append behavior first. It could be tightened slightly, but it earns its length.

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 3-parameter tool with 100% schema coverage and no output schema, the description covers everything an agent needs: what to do, when to call, prerequisite subscription, computation, storage side effects, and first-run behavior. Nothing important is missing.

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 coverage is 100%, so the schema already documents all three parameters. The description adds key nuance: seedAtl and seedCtl only matter on the first digest, seedCtl should be anchored to the user's watch value, and the date should be yesterday or earlier. That adds value beyond the raw schema.

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 states a specific verb and resource ('Builds a color-coded daily health digest') and clearly distinguishes it from sibling read-only tools like get_daily_activity or get_sleep by explaining it computes and appends a markdown history file rather than just returning API data.

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?

It explicitly says to use yesterday or earlier, notes today's data is usually incomplete, and explains that Sleep/Recovery API subscriptions are needed for those sections. It also says what falls back to 'no data' if subscriptions are missing, giving the agent clear when-to-call guidance.

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