set_email_flags

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

Beyond annotations, the description discloses unsupported flags (\Deleted, provider-specific), partial/ambiguous effects with per-ID status reporting, and no automatic retries. These are valuable behavioral traits that help the agent anticipate edge cases and errors.

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 three compact sentences: the first states the core action and scope, the second lists supported/unsupported flags, and the third covers prerequisite and failure behavior. Every sentence is informative and there is no redundancy.

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?

Given the output schema and annotations, the description covers essential purpose, constraints, prerequisites, and failure modes. It is complete for a mutation tool with partial effects, and it does not need to explain return values because the output schema is provided.

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 100% and every parameter has a clear description. The tool description adds only the prerequisite to use list_emails_metadata first, which indirectly relates to email_ids, but does not significantly enrich parameter semantics beyond the schema.

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 'Add or remove approved IMAP flags on one or more emails by email_id' with a specific verb and resource. It lists the supported flags, clearly distinguishing it from siblings like mark_emails_as_read.

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 provides a clear prerequisite ('Use list_emails_metadata first') but does not explicitly contrast with sibling mark_emails_as_read for \Seen flag operations. Usage is implied rather than explicitly differentiated, so a model might be unsure whether to use this tool or mark_emails_as_read for read/unread.

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