Modify Gmail Message Labels

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

Annotations already include destructiveHint: true, but the description adds valuable context by explaining specific behaviors: removing INBOX archives an email, and adding TRASH deletes it. This goes beyond the annotation to explain the mechanism of destructive actions. No contradiction with annotations.

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, consisting of two sentences. The primary purpose is front-loaded, followed by two clarifying use-case examples. No redundant or filler content.

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 moderate complexity (4 parameters, annotations, output schema), the description covers the essential purpose and key behavioral scenarios (archiving and deletion). It lacks explicit mention of the batch alternative and edge cases like simultaneous add/remove, but the structured schema and annotations cover the remaining details adequately.

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 input schema already covers all parameters with 100% description coverage. The description adds meaning by using concrete examples of add/remove label IDs (INBOX, TRASH) that clarify the real-world effect of the add_label_ids and remove_label_ids parameters, enriching the schema's bare definitions.

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 function: 'Adds or removes labels from a Gmail message.' This is a specific verb+resource combination. However, it does not explicitly distinguish itself from the sibling tool batch_modify_gmail_message_labels, though the singular 'a Gmail message' implies single-message scope.

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 concrete usage examples ('To archive an email, remove the INBOX label. To delete an email, add the TRASH label.'), which imply when the tool is useful. However, it does not explicitly state when to use this tool versus alternatives like batch_modify_gmail_message_labels, nor does it mention any exclusions. The guidance is helpful but not comprehensive for tool selection.

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