add_labels

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

With no annotations, the description adds the behavioral trait that labels are added without removing existing ones. However, it does not disclose what happens if a label already exists (e.g., idempotent or duplicate), nor any side effects or permissions needed, which limits transparency.

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: one sentence for purpose and two lines for parameter definitions. It is well front-loaded with the primary action, and every part is necessary.

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's simplicity (two required string parameters, no nested objects) and the existence of an output schema, the description covers the essential information: what the tool does and how to specify the inputs. It is complete for the task.

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 schema coverage is 0%, but the description explicitly defines the parameters: 'email_id: ID of the email' and 'mailbox_ids: Comma-separated mailbox IDs to add,' adding semantic meaning beyond the schema's type-only specification.

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 tool's action: 'Add one or more mailbox labels to an email (without removing existing ones).' It distinguishes itself from sibling tools like 'remove_labels' and 'bulk_add_labels' by specifying the additive nature.

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 such as 'bulk_add_labels' or 'remove_labels'. It does not mention when to avoid using it or any prerequisites.

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