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

'Acking twice is harmless' largely restates the idempotentHint=true annotation rather than adding new information. It does add a genuine behavioral effect beyond the annotations — acked messages are no longer offered — but says nothing about error behavior for unknown ids or the response shape.

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 short sentences, no filler, with the action and its effect front-loaded and the idempotency caveat last. Every sentence carries information.

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 two-parameter ack tool with no output schema, the description covers the workflow placement, the id source, and the no-op-on-repeat behavior. It omits what happens with invalid ids or whether any result is returned, which is a minor but real gap.

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 description coverage is 100%, so both parameters are already documented there, establishing a baseline of 3. The description only reinforces the source of `ids` ('Pass the ids heard_inbox returned') and adds nothing about bot_name or batching limits.

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?

States a specific verb (acknowledge) and resource (messages from heard_inbox), plus the consequence ('so they are not offered again'). The relationship to sibling heard_inbox is made explicit, letting an agent place it in the workflow without opening the schema.

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?

Gives a clear trigger condition: ack 'once you have acted on or accepted them', which also implies not to ack prematurely. It does not name when-not to use it or point at heard_report as an alternative, so it stops short of full routing guidance.

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