screenshot_file

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

The annotations declare readOnlyHint=true, meaning the tool should not modify its environment. The description says it 'saves the image into the output dir', which is a filesystem write. That directly conflicts with the read-only annotation, so the behavioral signal is misleading.

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, front-loaded with the tool's purpose and key behavioral distinction. No filler, and the parenthetical format detail is 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?

An output schema exists, so the return path need not be fully explained. But with 7 undocumented parameters, the description is not complete enough to guide correct invocation, especially for non-default options like selector, full_page, quality, and annotate.

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 0% across 7 parameters. The description adds meaning only for max_width and the format-follows-extension behavior; it leaves selector, full_page, quality, annotate, and filename unexplained.

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 states a specific verb and resource: it saves a screenshot image into the output dir and returns the path. It also clearly distinguishes this from the sibling screenshot tool by explaining that no image enters the context.

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 explicitly contrasts with screenshot via 'Like screenshot but...' and gives the selecting condition: use this when you want no image in context and a file path returned. It does not spell out when-not cases, but the alternative is named.

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