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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds real value beyond that: the paid prerequisite, the degraded unpaid response (a checkout URL for a human to open), and the fact that disclosure wording is generated per photo and per publishing surface. The licensee-obligation note is context rather than invocation guidance.

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 return payload, then the prerequisite, then a caveat — a sensible order with no padding. The final paragraph on publishing duty is somewhat tangential to calling the tool, keeping it short of a 5.

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?

With no output schema, the description carries the burden of describing returns and does so by naming all three deliverables. Prerequisite and failure-mode behavior are both covered; only the exact shape/format of the returned artifacts is left unspecified.

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?

Only one parameter, listing_id, and schema description coverage is 100% with a pattern and a clear explanation of where the id comes from in a listing URL. The description adds nothing about the id beyond the schema, so the baseline 3 applies.

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 and resource ('get the deliverables') and enumerates the three things returned: the archive download link, per-photo disclosure wording, and the public originals page. It implicitly separates itself from duskly_get_listing and duskly_get_checkout_url, 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 a clear precondition ('Requires the listing to have been paid for') and the alternative path when it isn't met ('An unpaid listing returns the checkout URL instead, for a person to open'). This is strong conditional routing, but it stops short of naming the sibling tool an agent should call instead.

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