sync_emails

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

Describes incremental sync with checkpoint reuse and metadata-only scope. Annotations only provide destructiveHint=false; description adds useful behavioral context beyond that.

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?

Three sentences with no redundancy; front-loaded with main action and incremental nature.

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?

No output schema, and description does not explain return values or sync behavior details. Adequate for a sync tool but could be more complete regarding results.

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 baseline 3. Description adds minor context for full parameter ("larger initial sample") but does not significantly enhance meaning beyond schema descriptions.

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?

Clearly states it incrementally syncs email metadata from IMAP to local SQLite index using checkpoints, distinguishing from siblings like run_background_sync.

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 advises when to use (before search_indexed_emails/get_threads when index stale), when not to (prefer run_background_sync for scheduled), and mentions full parameter for initial sample.

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