mark_flagged

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

With no annotations, the description carries full responsibility for disclosing behavior. It merely restates the name ('Star/flag' vs 'mark_flagged') and offers no information about whether the operation is reversible, idempotent, affects multiple emails, or requires specific permissions. This falls short for a mutation tool.

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 that clearly states the tool's purpose without redundancy. It could arguably include more context, but it is appropriately concise for a simple operation.

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 has one well-specified parameter and no output schema, so the description is the primary source of behavior. While it covers the basic purpose, it lacks usage guidance and behavioral transparency, which is notable given the sibling tools for read/unread/flag states. It is minimally viable but incomplete.

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?

The schema provides 100% coverage for the single 'uids' parameter with a description ('Email UIDs'), so the baseline is 3. The tool description adds no additional semantics beyond confirming it operates on emails, offering no format, constraints, or usage notes.

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 uses the specific verb 'star/flag' and identifies the resource as 'email(s)', clearly indicating the action of marking messages as flagged. It distinguishes from siblings like mark_read/unread and unmark_flagged through the positive flagging action, though it does not explicitly name an alternative.

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?

No guidance is provided about when to use this tool versus alternatives like mark_read, unmark_flagged, or move_email. There is no mention of prerequisites, scenarios, or exclusions, leaving the agent to infer appropriate usage.

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