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

The annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so safety is covered structurally. The description adds useful behavioral context about the mockups-folder scope, the excluded screenshot content, and the kinds of metadata returned, though it does not mention pagination or authorization requirements.

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 definition is two short sentences with the folder scope front-loaded and no wasted text. The exclusion and read-only note are concise and useful.

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 an output schema present and rich read-only annotations, the description is largely complete for this simple listing tool. The main minor gap is that it does not clarify includeMetadata behavior, though the schema documents that parameter adequately.

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 50%: includeMetadata is documented in the schema, while projectId is only conveyed through its UUID format. The description adds no direct explanation of either parameter, so it does not compensate much beyond what the schema already provides.

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 gives a specific verb and resource: listing image and video assets in the mockups storage folder. It also scopes this precisely against a likely alternative by stating that general project screenshots outside that folder are not 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?

It clearly implies when to use this tool by describing the exact folder scope and excluding general project screenshots. However, it does not explicitly name a sibling alternative such as list_screenshots or list_assets for the excluded content.

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