upload_next

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

With no annotations, the description carries the burden well: it discloses one-shot semantics, expiry after timeout_s, and that choosers are only intercepted while armed. It stops short of stating failure behavior once the lease expires, so not a 5.

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?

Dense but front-loaded, with the purpose first and operational caveats (one shot, expiry, interception scope, verification) following in short clauses. 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 stateful arming tool with no output schema or annotations, the description covers the mechanism, the arming window, and how to confirm status. A note on what happens at expiry would make it fully complete.

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 75%, so timeout_s, session, and lease are already documented. The description adds only the functional role of timeout_s (arm lifetime driving expiry) on top of the schema text; it adds little for lease/session.

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 precise verb+resource ('Arm the NEXT native file chooser with files') and includes the discriminating condition 'for upload buttons that have no input[type=file] in the DOM', which implicitly separates it from the sibling 'upload'.

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 full workflow ('Then click the button (any verb)') and the arming window, plus a verification path ('Check with upload_status'). It doesn't explicitly say to use 'upload' instead when a real input exists, but the no-input condition makes the boundary clear.

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