sync_coros_data

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

Beyond annotations, the description discloses cache side effects, incremental behavior after first sync, and timeout risks for large ranges. It also mentions the CLI alternative for backfills, which annotations do not convey. No contradiction with readOnlyHint=false or idempotentHint=true.

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 very concise: three sentences, each serving a clear purpose (what it does, post-sync behavior, usage advice). It is front-loaded with the core purpose and contains no fluff or redundant details.

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?

Despite having an output schema, the description covers essential behavioral context: cache population, downstream effects, timeout avoidance, and CLI alternative. For a sync tool with side effects and optional parameters, this is comprehensive and leaves no obvious gaps.

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% with both start_day and end_day described in detail (format, defaults, timezone). The description adds no additional parameter-level meaning beyond what the schema already provides, so the baseline of 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?

The description clearly states the tool syncs Coros data for a date range into a local SQLite cache, using a specific verb-resource pair. It distinguishes itself from read tools like get_daily_metrics by explaining its role as a cache population step.

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?

Explicitly explains when to use this tool (before reads), what happens after first sync, and gives alternative guidance for large ranges (segmenting) and initial backfill (use CLI). This directly contrasts with sibling tools and prevents misuse.

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