set_message_flag_status

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

With no annotations provided, the description carries the full burden and it does disclose a meaningful gate: explicit user approval is required before invocation. That safety context is valuable for a mutation tool. However it omits reversibility, whether the change persists server-side, and any rate or permission constraints, so behavioral disclosure is only partial.

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?

Two short sentences with zero filler, and the action is front-loaded ahead of the approval constraint. Every clause earns its place.

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?

The tool is fully self-describing on the input side thanks to the required const-constrained user_approved field at 100% schema coverage, and no output schema exists to explain. The description's approval statement is sufficient for correct invocation, but with no annotations it could add more about the mutation's effect and relationship to sibling flag tools.

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 account, mailbox, message_id, is_flagged and user_approved are all documented in the schema itself. The description adds no additional meaning such as message_id sourcing or flag semantics beyond what is already structured, so the baseline 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 states a specific verb and resource ('Flag or unflag a message'), which is clear and unambiguous. However it does not distinguish itself from sibling tools like set_message_read_status, which the agent must infer operates on a different flag.

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?

It gives a clear precondition ('Only call after the user explicitly approved this exact action'), which tells the agent when this tool is permissible. It does not name alternatives or contrast with set_message_read_status or move_message, so the routing guidance is partial rather than explicit.

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