incremental_sync

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

Annotations already declare read-only and non-destructive behavior. The description adds valuable behavioral context beyond that: the endpoint, the failure mode without valid sync tokens, and the expected payload shape including metadata:{caller}. No contradiction with annotations.

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 compact and front-loaded: purpose, endpoint/payload, failure condition, and sibling routing are all covered without filler. Every sentence adds information, and the parameter mapping at the end is a useful quick reference.

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 read-only two-parameter advanced sync tool, the description covers invocation details, preconditions, and routing. The lack of an explicit return-value description is a minor gap since no output schema is provided, but it does not block correct usage.

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 0%, so the description must compensate. It identifies sync_tokens_json and metadata_json, marks metadata as optional, and maps them to the endpoint body. It could specify the token JSON format more precisely, but the provided semantics are sufficient for basic invocation.

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 resource and action: 'Drive incremental calendar sync with sync tokens,' and names the exact endpoint and payload. It also differentiates itself from get_events, so an agent can identify when this tool is the intended one.

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?

Explicit guidance is provided: this is for advanced use, normal reads should prefer get_events, and calls without valid prior sync tokens often fail with 400. This gives a strong when-to-use and when-not-to-use signal relative to the large sibling list.

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