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

Annotations already supply readOnlyHint=false, destructiveHint=false and idempotentHint=true, and the description adds genuinely new behavior: closing another person's handoff is permitted, a note is expected to name what emptied it, and destruction is deliberately out of scope (the human discards in the panel). It does not say what state the handoff lands in after closing or whether the action is auditable.

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?

Front-loaded with the core rule in the first clause, but the middle sags: 'even when the handoff is someone else's' is restated by 'So this is also the call for someone ELSE's handoff,' and the panel aside is stylized. Efficient in content, but a sentence of redundancy survives.

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 3-parameter mutation with full schema coverage, no output schema and helpful annotations, the description covers selection, the companion call, and the prohibition adequately. Remaining gap is post-close state and any permission/ownership nuance for touching another person's handoff.

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%, so the baseline is 3; the description earns a bump by explaining the note's role ('with a note naming what emptied it', 'one line on what landed; it points at the residue') and clarifying that the handoff handle can come from the read or be a full id, which contextualizes the two required params.

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?

Specific verb (close) + resource (an open handoff) with a clear success condition: 'when its work is DONE.' It also implicitly distinguishes itself from arroway_log (used alongside, not instead) and from human panel discard. It stops short of naming a sibling explicitly (e.g. arroway_pass, arroway_withdraw), so it is clear but not fully differentiated.

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 the trigger ('work is DONE'), the companion call (arroway_log records the residue), an extended case (removing what a handoff exists to fix, closing even someone else's handoff), and an explicit prohibition ('a handoff that still carries real work … must never close') plus the correct alternative (discarding is the human's gesture, in the panel).

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