ack

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

The description discloses the behavioral effect: signals to the sender that the agent has received and is working on the message. It also implies no submission occurs. However, it is missing details on idempotency, rate limits, or authentication requirements, but the disclosed behavior is sufficient given the tool's simplicity.

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 two sentences long, front-loaded with the core purpose, and every sentence adds value. No wasted words.

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 simple one-parameter tool with an output schema, the description covers purpose, usage guidelines, and a key behavioral trait. It lacks mention of error conditions or output format, but the output schema likely covers that. Overall adequate for the context.

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?

The description does not explain the parameter 'a2a_task_id' beyond its name. With 0% schema description coverage, the tool description should add meaning, but it fails to state that this parameter identifies the incoming DM or task. The agent has no additional context from the description.

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 the tool acknowledges an incoming DM without replying, distinguishing it from the sibling 'reply' tool. The verb 'acknowledge' and resource 'incoming DM' are specific and unambiguous.

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?

Explicitly states when to use this tool vs the alternative 'reply': most flows prefer 'reply', and 'ack' should be used only when wanting to think before replying. This provides clear guidance.

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