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

Beyond the annotations (readOnly, idempotent, non-destructive, closed-world), the description discloses the hard constraint that it only works for orders created in this session, that upload slots map one per line, and how the returned URL surfaces to the user (markdown hyperlink, 'Open upload page' button on the card). That is behavioral context an agent cannot get from the structured fields.

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 purpose, then usage, then presentation mechanics; the ordering is sensible and there is little filler. The final paragraph on markdown linking and the upload card is longer than strictly needed for tool selection, though it is operationally useful.

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-shape explanation is correctly omitted, and the description covers eligibility, alternatives, and one presentation gotcha. The remaining gap is that the two required identifiers are never explained, which matters for a fresh agent with no parameter documentation.

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% for two required parameters, so the description carries the full burden. It only indirectly gestures at session scoping ('orders created in this session') and says 'an existing order'; neither session_id nor order_id is defined, and their format/provenance is never stated.

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?

The first sentence names a specific verb and resource ('Return a browser page where the user uploads their finished artwork files ... for an existing order') and even specifies the accepted file types and the one-slot-per-line structure. It separates itself from design_start_for_order and the design upload siblings by scope (finished artwork vs. design needed).

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?

Explicit when-to-use ('user already has finished artwork and doesn't need a design from us'), explicit alternative when not ('for a design, use design_start_for_order instead'), plus the prerequisite that a line needs one or the other before payment. It also gives two negative instructions (don't ask for a local path, don't claim files can't be accepted) and the session constraint.

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