modify_email

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

No annotations are present, so the description carries the full burden of behavioral disclosure. It only says 'Modify email labels' and offers a folder metaphor, but it does not reveal whether label changes replace existing labels, whether add/remove parameters are cumulative, what side effects occur on the message, or what response to expect from a mutating operation.

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?

A single sentence with no filler; the parenthetical clarifies the domain concept of labels as folders. The core action is front-loaded, making it easy to scan.

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 presence of four parameters with overlapping semantics (label_ids vs add/remove), the tool's mutation behavior needs more context. The description lacks guidance on how the three label parameters interact, whether this is single-message only, and what the output schema contains. The existing output schema reduces the need to explain return values, but this is still incomplete for a mutating tool.

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 schema already documents each parameter individually. The description adds only a generic labels/folders mapping and does not clarify the semantic difference between label_ids, add_label_ids, and remove_label_ids, but the baseline 3 is appropriate because the schema handles parameter documentation.

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 action ('Modify email labels') and clarifies the resource ('email') and conceptual scope ('move to different folders'). It is clear enough to distinguish from unrelated sibling tools like send_email or create_filter, though it does not explicitly single out batch_modify_emails as a sibling for bulk operations.

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?

There is no guidance on when to use this tool versus alternatives such as batch_modify_emails or trash_email. The description implies it is for modifying labels, but it does not state exclusions, prerequisites, or single-vs-batch usage conditions.

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