capture_now

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

Discloses return contents (metadata fields) and explicitly states what is NOT returned (image bytes), which is crucial for correct use. No contradictions with annotations (none provided).

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 sentences, no redundant words, critical information (action, return, alternative) presented efficiently. Every sentence earns its place.

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?

Covers all necessary information: action, return (with specific metadata fields), and clear alternative for image bytes. No gaps given the tool's simplicity.

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?

Tool has no parameters; schema coverage is 100%, so no additional parameter semantics are needed. Baseline 4 as per rules.

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 the specific action ('Take a single screenshot on demand') and clearly distinguishes it from sibling tool analyze_screen by noting what it does not return and where to get the image.

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?

Provides explicit guidance to use analyze_screen for image content, differentiating the primary use case. Lacks guidance for other sibling tools but suffices for the most relevant alternative.

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