Screenshot

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

Annotations already declare readOnlyHint=true and openWorldHint=true, which cover the safety profile. The description adds only that it performs no UI element parsing, a useful behavioral distinction, but it says nothing about return formats, serial handling, or path behavior.

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, focused sentence with no fluff. It is front-loaded with the core action and immediately differentiates from siblings.

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?

The description is too thin to enable correct invocation: it omits param semantics, output behavior, and device targeting. With optional params and no output schema, the agent is left guessing.

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%, and the description mentions none of the three parameters (mode, path, serial). With no compensation from the description, the agent has no understanding of parameter meanings or options.

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 clearly states the verb ('Capture') and resource ('a screenshot'), and the qualifier 'without UI element parsing' distinguishes it from sibling tools like inspect and findElement. This provides immediate clarity on what the tool does.

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?

The phrase 'without UI element parsing' establishes when to use this tool (raw screenshot capture) and implies it's not for UI analysis. However, it doesn't explicitly name alternatives or state when not to use it, so it lacks explicit exclusion guidance.

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