bulk_action

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

With no annotations, the description carries the full burden and does so: delete is recoverable via Deleted Items and never permanent, archive targets the Archive folder, move requires destinationFolderId, and the default and hard cap on max are stated. It also flags that the dry-run sample contains untrusted email content that must not be followed as instructions.

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?

Front-loads the action and the mandatory dry-run safety step, then moves through selection modes, limits, action semantics, and the untrusted-content warning. It is dense but every clause conveys operational information an agent needs before calling.

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?

For an 11-parameter mutation tool with no output schema and no annotations, the description still covers safety, scoping, limits, per-action effects, and the shape and risk of the dry-run response. Nothing an agent needs to call this correctly is missing.

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?

Adds real meaning beyond the 73%-covered schema: the schema says query cannot combine with filters, but the description names which filters and explains the default scope difference (inbox for filters, whole mailbox for query). It restates the max default and cap already in the schema, so it falls just short of full marks.

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?

Opens with a specific verb and resource ('Apply one action ... to every message matching a search') and enumerates the seven allowed actions. This clearly separates it from single-message siblings such as delete_message, move_message, mark_read and flag_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?

Gives explicit when-and-how guidance: always run with dryRun first, confirm the matched count with the user, then re-call with dryRun: false. It also states the mutually exclusive selection modes (query vs filters cannot be combined) and points to the right parameter for move.

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