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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false, and destructiveHint=false, so safety is covered. The description adds genuine behavioral context beyond that: results are name-ordered consistently (a stable sort guarantee) and the listing includes files nested inside upload folders, plus the cursor-based paging mechanism.

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?

Two tight sentences with the scope front-loaded before the pagination note. There is mild redundancy between the header line 'List saved media' and the opening clause 'List your saved images, videos, and audio', but the second sentence carries new information rather than filler.

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 read-only, three-parameter list tool with no output schema, the description covers scope, ordering stability, and paging, which is most of what an agent needs. It omits the response shape and whether any auth/account context is required, but those are minor for this tool class.

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 only 33% — only 'cursor' is documented, as 'Opaque nextCursor from the previous page; keep the same filters.' The description reinforces the cursor flow but adds nothing about 'type' filtering semantics or the 1–100 'limit' bound, so it only partially compensates for the coverage gap.

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 saved media') and enumerates the covered media kinds (images, videos, audio) plus upload-folder contents, which meaningfully separates it from the narrower listVideos sibling. It stops short of naming siblings explicitly, so an agent must infer the boundary with searchMedia/listVideos.

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?

Usage is implied by 'List your saved images, videos, and audio, including files inside upload folders' — the agent can infer this is the broad saved-media enumerator — but there is no explicit when-to-use versus searchMedia or listVideos, and no exclusions. The only guidance given ('use nextCursor for subsequent pages') concerns pagination, not tool selection.

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