gws.mail.modify_message

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

Annotations indicate readOnlyHint=false and destructiveHint=false. The description adds semantic context by mapping label changes to actions like archiving and read/unread status. It does not disclose error scenarios or authorization requirements, but annotations already cover the safety profile, so score 4.

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?

Single sentence of 19 words, front-loads the core action, includes useful examples, and uses no filler. Highly concise.

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 mutation tool with well-documented schema and no output schema, the description covers common workflows (archiving, starring, read/unread, custom labels). It gives enough context for an agent to select and invoke 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?

Input schema provides 100% coverage for all 4 parameters, each with clear descriptions. The description does not add further parameter-level detail beyond the schema examples, so baseline 3 is appropriate.

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?

Description clearly states 'Add or remove labels from a Gmail message' with a specific verb and resource. It distinguishes from sibling tools like gws.mail.read_message and gws.mail.create_draft by focusing on label modification. Examples of archiving, starring, and marking read/unread clarify the 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?

Provides explicit use cases: 'use for archiving, starring, marking read/unread, or applying custom labels'. This tells when to invoke the tool. Does not specify alternatives or exclusions, but the use cases are clear, earning a 4.

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