list_screenshots

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

With no annotations provided, the description carries the full behavioral burden and does not meet it. It doesn't disclose whether listing is recursive, whether it errors on a missing directory, whether results are sorted or paginated, or what a returned entry looks like.

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?

A single short sentence with no filler and the resource front-loaded. It is efficient, though it is arguably too terse rather than over-long, so it doesn't earn a 5.

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 one-optional-param read tool with a fully described schema and no output schema, this is minimally adequate. Missing return-value shape (filenames vs. full paths) and error behavior on a nonexistent directory are the notable gaps.

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 one optional parameter whose schema description already gives the default ('./screenshots'). The phrase 'output directory' adds only a mild framing hint that the default is the tool's own output location, so this lands at the 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 all screenshots') with a location qualifier ('in the output directory'), so the agent knows exactly what operation it performs. However, it never distinguishes this from siblings like get_ui_screens or capture_screenshot, which an agent could reasonably confuse it with.

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?

There is no statement of when to use this versus alternatives — nothing says to call it before capture_screenshot to check existing files or instead of get_ui_screens. The only implied guidance is that it reads a directory, which the agent must infer from the name.

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