Modify message

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

Annotations already convey that this is a mutating yet non-destructive, idempotent operation. The description adds concrete examples of those mutations, but it does not disclose deeper behaviors such as Gmail-only label restrictions, the relationship between folder and move_to, or whether modifications must be specified one at a time.

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, tightly worded sentence that front-loads the verb and action list. There is no filler or repetition, and every operation mentioned maps to a real parameter or side effect.

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?

With nine parameters and no output schema, the description is too terse for reliable invocation. It leaves unclear how folder, move_to, and archive interact, whether at least one modification must be selected, and which operations are Gmail-only. An AI agent would still face significant ambiguity when constructing a call.

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 description loosely maps 'read/unread' to seen and 'star/unstar' to flagged, which adds some meaning for parameters that lack schema descriptions. However, most parameter meanings are already covered by the schema, and the description does not clarify ambiguities like the difference between folder and move_to, so it does not substantially exceed schema coverage.

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 begins with specific verbs and a clear resource: it can mark read/unread, star/unstar, add/remove Gmail labels, and move/archive a message. This concrete action list makes it easy to distinguish from siblings like get_message, search, or trash_message.

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 explicit guidance on when to use this tool versus alternatives. It does not mention, for example, that trash_message should be used for deletion, or that folder paths can come from list_folders. Usage context must be entirely inferred from the action list.

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