set_flags

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

With no annotations, the description carries the full burden. It discloses that flags can be added/removed and that a confirmation is returned. However, it does not mention idempotency, error handling, or prerequisites like authentication or folder existence.

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 fairly concise but includes an 'Args' block that breaks the typical MCP narrative flow. It could be tightened by integrating the parameter explanations into a single paragraph without line breaks.

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 description covers the basic operation and parameters but omits context like error scenarios, rate limits, and best practices. Without annotations or output schema, the agent is left with gaps in understanding the tool's full behavior.

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 0%, so the description provides the only documentation for parameters. It explains that 'email_id' comes from search_emails, and 'add'/'remove' are arrays of flags. However, it lacks details on folder format, flag validation, and behavior when both add and remove are specified.

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 'Set or clear IMAP flags on a message' and lists common system flags. It differentiates the tool from its sibling 'bulk_set_flags' by implication (single email), but does not explicitly contrast them.

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 on when to use this tool versus bulk alternatives or other flag-manipulation tools. The description assumes the agent knows to use this for single messages, but does not state that explicitly.

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