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

Annotations already cover read-only, idempotent, non-destructive behavior, and the description adds meaningful scope: about 120 recent items scanned, broken links skipped, default/max return size, and exact media fields plus count. This is strong disclosure beyond structured hints.

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?

The description is front-loaded with the core action and scope, then quickly handles return shape, alternative routing, scanning behavior, and limits. It is dense without being bloated.

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 listing tool with full annotation coverage and full schema coverage, the description supplies enough context: source scope, return fields, scan limits, broken-link behavior, and sibling routing. No output schema is needed given the explicit field list.

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 both parameters are already documented. The description reinforces the effective limit range but does not add workspaceId semantics beyond what the schema states, making 3 the appropriate baseline.

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 images/videos from posts the connected accounts already published, newest first, with named return fields. It also distinguishes the key sibling list_library_media and clarifies that externally published posts are included.

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 says to use this tool to reuse real brand photos instead of generating new ones, and directs the agent to list_library_media for files uploaded to or generated in Ignix. That gives both a use case and a concrete alternative.

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