ack

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

With no annotations, the description carries full behavioral burden. It hints that active leases require a valid token, but says nothing about idempotency, what state transitions ack triggers, whether it's destructive, or what happens on a failed/expired lease.

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?

A single compact sentence with the core action front-loaded and no filler. It is efficient, though brevity comes at the cost of substance rather than through careful editing.

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?

An output schema exists so return values needn't be explained, but for a state-changing acknowledgment tool with zero annotations and fully undocumented parameters, the description leaves critical call-time details (valid states, token requirement, error handling) unaddressed.

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 0% across 4 parameters. The description obliquely references state ("confirm the state") and lease_token ("the right token") but never explains valid state values, the message_id target, or the purpose of the error field, so it fails to compensate for the coverage gap.

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?

"Confirm the state of your own delivery" conveys the resource (a delivery/message) and the act of acknowledging it, but the verb is fuzzy and it never states what an acknowledgment actually does or how it differs from siblings like accept, claim, or release.

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 clause "an active lease needs the right token" implies a precondition for one scenario, but there is no guidance on when to use ack versus accept, claim, release, retry, or cancel, and no statement of exclusions.

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