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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely new behavioral context: this call terminates a sequence and is optional, so skipping it does not break the workflow.

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?

Two short sentences, front-loaded with the action and followed by the optionality caveat. 'Closing the sequence' slightly restates 'final part', a minor redundancy in an otherwise waste-free description.

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-param, idempotent ack call with no output schema, the description covers what it does, when to call it, and that it is optional. It does not say what happens if the receipt is stale or the call is skipped, but nothing essential to invoking it is missing.

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 read_id and receipt are already documented as opaque values with their provenance. The description only restates that they are supplied together, adding no syntax or format detail beyond the schema.

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/confirm) and resource (the final part of a multi-part Arroway read) and explains the effect: closing the sequence. This is enough to separate it from arroway_read and arroway_continue, though it never names those siblings explicitly.

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 clear context for use (after the final part of a multi-part read) and an explicit non-requirement: 'It is not a precondition for working.' That tells the agent not to block on this call, but no alternative tool is named for related cases.

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