bulk_update_flags

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

Annotations already indicate idempotentHint=true and destructiveHint=false. The description adds that it's a bulk operation and references the flag whitelist, but does not cover transactional behavior, partial failures, or rate limits. Given annotation coverage, this is adequate but not exceptional.

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 extremely concise: two sentences with no redundant words. It front-loads the core purpose and follows with essential usage constraints. Every sentence carries weight.

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?

While the description covers the main points for a bulk flag operation, it lacks details on return value, error handling, behavior for empty selections, or atomicity. Given the complexity (6 params, nested object) and absence of output schema, more completeness would be helpful.

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% with detailed descriptions for each parameter. The description adds no new parameter information beyond summarizing the requirement. Baseline 3 is appropriate.

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 clearly states the verb 'add or remove flags' on 'multiple messages in one operation', effectively distinguishing it from the single-message sibling 'update_message_flags'. It also specifies the required inputs and mutual exclusivity.

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 explicit instructions on how to provide inputs (EITHER uids OR match, plus at least one flag operation). It references the flag whitelist from update_message_flags. However, it lacks explicit guidance on when to use this tool over alternatives like bulk_update_labels.

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