apply_thread_action

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

No annotations are provided, so the description bears the full burden. It discloses that actions are reversible, mentions key parameters (dryRun, unreadOnly, syncBefore) that affect behavior, and implies the action is applied to every message in the thread. However, it does not detail what happens on error or if the threadId is invalid.

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 brief—two sentences—and front-loads the core purpose. Every sentence adds value: the first explains the operation, the second provides usage context and parameter hints.

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 complexity (7 parameters, no output schema), the description covers the main purpose, when to use, and key parameters. It does not explain the return value or potential errors, but the sibling list and schema provide some context. Overall, it is adequate for an agent to select and invoke the tool 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?

Schema coverage is high (86%), so the baseline is 3. The description adds context beyond the schema by explaining the purpose of dryRun (preview impact), unreadOnly (scope to unread messages), and syncBefore (refresh index first). This adds meaningful semantic value.

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 states the tool applies a reversible mailbox action to every message in a normalized thread at once, using examples like archive or mark-read. It explicitly differentiates from sibling batch_email_action, which handles explicit emailIds rather than a threadId.

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 includes explicit guidance: 'Use when you want to act on a full thread identified by threadId' and 'Prefer batch_email_action when you have explicit emailIds rather than a threadId.' This clearly indicates when and when not to use the tool.

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