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

With no annotations, the description carries the full disclosure burden. It mentions the message cap, return of the updated thread, and authentication requirements. It doesn't detail rate limits or error handling, but the disclosed cap is a key behavioral trait for a follow-up tool.

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?

Three concise sentences cover purpose, usage guideline, and authentication/details. No redundant information; every sentence adds value. The structure is front-loaded with the main action.

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 3 required parameters, no output schema, and no annotations, the description provides necessary context: purpose, prerequisite (contact_business), cap, and authentication. It could briefly note that message is the content, but that's in schema. Overall adequate.

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 descriptions for each parameter. The description adds value by explaining that token and conversation_id come from a prior contact_business call, providing context beyond the schema. This clarifies the parameter relationships.

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 explicitly states the tool adds a message to an existing conversation opened with contact_business, distinguishing it from sibling tools like contact_business (which opens the conversation) and check_replies. The verb 'add' and resource 'message to conversation' are clear.

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 warns about a message cap per conversation, guiding the agent to send one considered follow-up rather than fragments. It also notes the required authentication and the need for conversation_id and token from contact_business, implying that contact_business should be called first. However, it doesn't explicitly list alternatives or when not to use.

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