sync_emails

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

Beyond the destructiveHint annotation, the description discloses a critical behavioral limitation: incremental sync never notices archived, trashed, or moved messages, so stale entries can persist indefinitely. It also explains exactly what full:true changes, giving the agent important operational knowledge not available from annotations alone.

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 dense but well-structured: it front-loads the core purpose, then adds necessary caveats and usage guidance. Every sentence contributes meaningful information, and the length is justified by the tool's nuanced behavior.

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 sync tool with four optional parameters, no output schema, and important staleness caveats, the description covers the essential operational context: when to run it, what it does, what it misses, how to fix that with full:true, and which sibling to prefer for scheduled sync. This is complete for an agent to select and invoke it correctly.

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 the schema already documents all four parameters well. The description reinforces the meaning of full and folder but does not add substantial new parameter-level semantics beyond what the schema provides, so the baseline of 3 is appropriate.

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 opens with a specific verb and resource: 'Incrementally sync email metadata from IMAP into the local SQLite index.' It clearly distinguishes this tool from siblings by explaining the checkpoint-based incremental mechanism and explicitly positioning it relative to search_indexed_emails, get_threads, and 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?

The description gives explicit usage context: use before search_indexed_emails or get_threads when the index may be stale. It also directs users to prefer run_background_sync for scheduled syncs and explains when to set full:true, providing clear alternatives and conditions.

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