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

Annotations already declare readOnlyHint=false, destructiveHint=false, and idempotentHint=false. The description adds that it only prepares an internal Workroom channel, which clarifies side-effect scope, but does not disclose return values, permissions, or behavior when a thread already exists. With annotations covering the safety profile, this is adequate but not rich.

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 three sentences, front-loaded with the core action. 'Use this when...' and 'This only prepares...' provide essential guidance without unnecessary detail.

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 find-or-create tool with three parameters and an output schema, the description provides purpose, usage context, and scope. It does not need to explain return values due to the output schema, and parameter defaults are in the schema. The only minor gap is unspecified behavior on creation versus finding, but overall it is complete.

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 100% with descriptive parameter definitions for agentId, userId, and title. The description adds no parameter-specific meaning, so the baseline 3 applies.

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 a specific action—'Find or create a Workroom DM thread'—with the involved parties (merchant user and AI colleague). This clearly distinguishes it from siblings like post_workroom_message, which handles messaging rather than thread preparation.

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 gives an explicit condition: 'Use this when an inbound event deserves owner attention but no threadId was provided.' It also notes scope with 'This only prepares an internal Workroom channel,' implying it is not for sending messages. However, it does not name an alternative tool explicitly, stopping short of a 5.

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