gmail_update_label

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

With no annotations provided, the description carries the full burden for behavioral disclosure. It adds valuable context: the system-label restriction and the full-scope auth requirement. However, it doesn't disclose mutation semantics such as whether omitted fields remain unchanged, error behavior when attempting to update a system label, or whether changes are reversible — significant gaps for a write tool with no 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 two sentences with front-loaded purpose, followed by a constraint and an auth requirement. No wasted words; every clause adds information.

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?

The tool has 7 parameters and no output schema or annotations, making it a moderately complex operation. The description covers purpose, a key constraint, and auth scope, but leaves open questions about update semantics (partial updates?), failure modes (system label attempt), and what the caller receives in the response. Adequate for selection and basic invocation, but not for fully understanding the operation's behavior.

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. The description's 'rename, change color, visibility' loosely maps to name, textColor/backgroundColor, and labelListVisibility/messageListVisibility, but it doesn't add meaning beyond the schema's per-parameter descriptions (e.g., hex format, enum choices, or partial-update behavior). The schema already documents each parameter thoroughly.

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 uses a specific verb ('Update') and resource ('Gmail label') with explicit operation scope (rename, change color, visibility). It clearly distinguishes from sibling tools like gmail_create_label (create), gmail_delete_label (delete), and gmail_modify_labels (which modifies labels on messages rather than the label definition itself). The system-label exclusion further clarifies 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 clear context: it can only modify user-created labels ('System labels cannot be modified') and requires full OAuth scope ('Requires full scope'). This gives the agent actionable constraints for deciding when to call it, though it stops short of explicitly naming alternatives like gmail_create_label or gmail_delete_label for related operations.

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