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

Annotations declare read-only/non-destructive, but the description adds substantial behavior the annotations cannot: newest-first ordering, case-insensitive search scoped to file name only, no other sorting, and the critical divergence that the cabinet Media screen reads a different service so listings may differ both ways.

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 purpose, then capabilities, then limitations. It is longer than average, but the limitation warnings (no rename, avoid delete-and-reupload) are load-bearing rather than padding; a slight trim of the example questions would lose nothing.

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 still covers ordering, search semantics, pagination defaults (via schema), what it returns (file id, URL), and what it cannot do, which is everything an agent needs to call it correctly and to avoid fabricating rename support.

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% with defaults and bounds already documented, so the baseline is 3, but the description adds real semantic value: search is a case-insensitive match on file name only, which sharpens the schema's terser 'Filter by file name'.

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 ('List the image files stored on the merchant's account') and implicitly distinguishes itself from hub_upload_media and hub_delete_media_file by noting it is the source of a file id before deletion and a URL for reuse.

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?

Explicitly frames the questions it answers ('what images do I have', 'do I already have a photo of X'), states when to reach for it (getting a file id or URL), and gives clear negative routing: renames/alt text/title/folder changes must happen on the Media screen, and deleting-and-reuploading to fake a rename is prohibited.

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