library_images

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

With no annotations supplied, the description carries the full disclosure burden. It does add useful behavioral context — the *_ref values are short references and are only valid for the duration of this MCP service run — but it never says the call is a read-only, side-effect-free lookup, nor does it discuss result size or ordering; the video/audio reference note appears to be generic boilerplate unlikely to apply to this tool.

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 first sentence is well front-loaded and earns its place. The second paragraph about img:/video: short references reads as shared boilerplate pasted across tools, and its video/audio clause is not clearly relevant here, so it dilutes rather than sharpens the definition.

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?

There is no output schema, so the description must explain what comes back — and it does, describing a per-card set of result images enumerated by image_index. Combined with the reference-lifetime caveat, an agent has enough to call it and hand the refs to image_view; only the read-only nature is left implicit.

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 100%, so instance_id, template_id and project_path are already fully documented, including the instance_id/project_path either-or. The description only restates the template_id provenance that the schema already states, adding no new meaning.

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 identifies the resource precisely: the full set of result images for an AI image card (kind=ai_image), with each image_ref numbered by image_index. It also names the sibling tools it pairs with (image_view, library_apply, library_list/library_search), so it is distinguishable. It lacks an explicit verb (it reads as a noun phrase rather than 'list/get'), which slightly blunts the action.

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 concrete routing: use image_view to look at the images, use library_apply with the image_index to apply one, and template_id must come from this session's library_list/library_search. That is clear when-to-use and prerequisite guidance, though it never states a when-not-to-use condition.

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