update_label

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

Annotations already indicate destructive and non-read-only behavior. The description adds context that message membership is unaffected, which is a key behavioral detail beyond annotations. No contradictions detected.

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?

Two sentences pack the essential information: the action, the resource (exact current name), the scoped changes (rename/visibility), and a clear exclusion. No redundancy or fluff.

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?

For a simple update tool, the description covers the main functionality and exclusions. An output schema exists (not shown), so return values are handled. Could mention authentication or label scope, but overall complete enough to use correctly.

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?

With only 25% schema description coverage, the description provides high-level context (e.g., 'rename the label or change its Gmail visibility settings') that maps to parameters like new_name and visibility enums. It partially compensates for the low coverage but does not detail each parameter's exact meaning.

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 'Update one Gmail user label' with the specific action of renaming or changing visibility. It distinguishes from sibling tools like create_label and delete_label by specifying what it does not do (modify message membership).

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 explains what the tool does and explicitly states what it does not modify, guiding the agent on appropriate use. However, it lacks direct comparison to siblings (e.g., when to use update vs create/delete) and does not mention prerequisites like authentication.

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