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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuinely new behavioral context: the output is a download link rather than inline data, blank input has unbounded scope, and it requires a Cotlet API key with app access.

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?

Three tight, front-loaded sentences where each contributes (what it returns, scoping rule, auth requirement). The leading 'Pirate Ship:' restates the title and is mild waste, but nothing else is padded.

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 return shape ('spreadsheet download link') and the auth prerequisite, which is enough for an agent to call it correctly. Minor gap: it doesn't note whether the link expires or the export is async.

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, but the description adds real semantic value: it explains that an empty search exports all label purchases to date, which is behavior the schema's 'Same search as list_shipments' does not convey.

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 description names a specific verb+resource: it exports the current shipments grid as a spreadsheet download link. It is clear about scope ('all rows of the current filter or search'), but it does not explicitly name the sibling list_shipments as the non-export alternative, so an agent must infer the distinction.

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?

It gives a useful edge-case rule ('a blank search exports every label purchase to date'), which implies usage, but it never states when to reach for this export versus list_shipments or get_shipment. Guidance is implied rather than explicit.

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