bulk_apply

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

Annotations already declare destructiveHint=true and readOnlyHint=false. Description adds no new behavioral traits such as idempotency, rate limits, or response details. It is adequate but does not go beyond what annotations provide.

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?

Two sentences, no wasted words. First sentence defines purpose and actions, second adds essential condition for move. Front-loaded and efficient.

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 4 parameters and no output schema, the description covers the action and parameter hints but doesn't explain the response or error handling. Adequate but could be more complete.

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?

100% schema coverage means parameters are already described. The description adds value by emphasizing that 'move requires destination_mailbox' and clarifying that message_ids can include angle brackets, which is helpful context 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?

Description clearly states the tool applies one of six specific actions to a list of messages in a single batched call, and highlights it's faster than alternatives. The verb 'Apply' and resource 'messages' are explicit, and it distinguishes from sibling tools by being a unified bulk action.

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?

Description says when to use: for applying the same action to multiple messages efficiently. It notes the requirement for 'destination_mailbox' when op is 'move'. However, it doesn't explicitly state when not to use (e.g., different actions per message) or compare to sibling bulk tools like bulk_flag.

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