imap_update_message_flags

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

No annotations are provided, so the description must disclose behavioral details, but it only says flags can be added or removed. It does not state whether existing unlisted flags remain unchanged, exactly when both add and remove are allowed together, or what errors or side effects may occur.

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 a single front-loaded sentence with no filler, making it appropriately concise. It is slightly too terse to be fully self-sufficient, but it structurally keeps the essential operation at the front.

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?

While the input/output schemas cover parameter and return semantics, the description omits the contextual layer: no guidance on single-message versus bulk use, no side-effect disclosure, and no distinction from the highly similar sibling `imap_bulk_update_flags`. Given the number of IMAP siblings, this is a meaningful completeness gap.

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 parameters already document `add_flags`, `remove_flags`, `message_id`, and `account_id`. The description adds no parameter-level detail beyond restating the add/remove operation, so the baseline score 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 operation as adding or removing IMAP flags, so the action and resource are identifiable. However, it does not distinguish single-message behavior from the sibling `imap_bulk_update_flags`, leaving some differentiation to inference.

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 no when-to-use or when-not-to-use guidance, and names no alternatives. Nothing indicates when to choose this tool over `imap_bulk_update_flags`, `imap_search_and_delete`, or other flag-related siblings.

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