Capture Roblox window

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

The annotations already declare readOnlyHint=true and idempotentHint=true. The description adds useful context about the operating mechanism ('local Windows APIs'), the output type ('MCP image content'), and a prerequisite that the window must be visible. It does not cover error handling or edge cases, but given the annotations cover the safety profile, this is a meaningful addition.

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 description is one well-structured sentence that opens with the primary verb and delivers all key information without filler. It is highly scannable and efficient.

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 covers the core purpose and output format, which is adequate for a simple capture tool. However, it fails to clarify how the optional 'pid' parameter behaves (e.g., whether it is needed for multi-window scenarios or when omitted), and it does not address failure modes such as a missing or hidden window. This leaves gaps for reliable invocation.

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?

The schema includes a single 'pid' parameter with no description, and the description does not mention it or explain how it selects the Roblox window. Since schema description coverage is 0%, the description was expected to compensate, but it leaves the parameter's purpose and optionality completely ambiguous, forcing the agent to infer from the property name alone.

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 precisely states the action ('Capture a real PNG'), the target ('a visible Roblox window'), the method ('through local Windows APIs'), and the output format ('return it directly as MCP image content'). This makes it distinct from sibling tools like capture_re_snapshot or smart_snapshot, which likely return UI trees or structured data.

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 emphasis on 'real PNG' and 'visible Roblox window' implies this tool is for pixel-accurate screenshots, but it does not explicitly name alternatives or state when not to use it. Sibling tools such as list_roblox_windows or capture_re_snapshot are not referenced, so guidance remains implicit rather than explicit.

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