imap_bulk_update_flags

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

With no annotations, the description carries the full burden of behavioral transparency. It mentions the limit of 500 messages, which is good, but it does not disclose that the operation is a write/mutation, whether it is reversible, what happens on partial failures, or whether it requires authentication. The description gives a minimal hint of scope but lacks deeper behavioral context.

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 a single sentence, efficient and to the point. It front-loads the key action and limit. However, it is under-specified in other dimensions, relying heavily on the schema, which is acceptable for conciseness. It earns a 4 because it is appropriately sized for a simple tool.

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 tool has 4 parameters and no annotations, the description is incomplete. It does not mention any error handling, partial updates, or the need for at least one of add_flags or remove_flags. The output schema exists but the description does not explain what the response contains. For a bulk operation, it should provide more context about batched behavior and side effects.

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 baseline is 3, but the description itself does not add any meaning beyond the schema. The schema already explains that 'message_ids' must be from the same mailbox and 'add_flags' and 'remove_flags' are optional. The description does not clarify the relationship between add_flags and remove_flags (e.g., whether at least one must be set) or provide examples. It adds no value beyond the schema, so I dock to 2.

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 says 'Update flags on up to 500 messages in one operation', which identifies the action (update flags) and the resource (messages), but it does not distinguish this tool from its sibling 'imap_update_message_flags'. Given the sibling exists, the description should specify the bulk nature as a differentiator; it does state 'up to 500 messages' but lacks explicit contrast. This is clear but not fully differentiating.

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 no guidance on when to use this tool versus alternatives. Siblings like 'imap_update_message_flags' suggest a single-message alternative, but the description does not mention it or any conditions for choosing one over the other. There is no mention of limitations like 'message_ids must be from same mailbox' (that is in schema), and no exclusions.

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