Capture device screenshot

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

Annotations already declare readOnlyHint=true and destructiveHint=false, indicating safe read operation. Description adds that the command runs `adb exec-out screencap -p` and saves a file to a specific directory, providing context about file creation. However, it does not disclose potential failure modes or prerequisites (e.g., device must be connected).

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?

Three concise sentences, each serving a distinct purpose: action and output, return value, and default directory. Information is front-loaded with the core functionality first. No redundant or verbose content.

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 simple, read-only tool with one optional parameter and full annotations, the description covers the essential aspects: what it does, how it works, where output is saved, and what is returned. No output schema required as return value is clearly stated.

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 100% for the single parameter 'serial', with a clear description of its default behavior. The tool description adds no additional parameter semantics. According to guidelines, baseline 3 applies when schema coverage is high.

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?

Description clearly states it captures device screen via adb, saves PNG to configured directory, and returns absolute path. The verb 'captures' and resource 'screenshot' are specific and unambiguous. Distinguishes from siblings like devilge_dump_ui by focusing on visual screenshot capture.

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?

No explicit guidance on when to use this tool versus alternatives like devilge_dump_ui or devilge_get_logcat. The description only describes the action without context of typical use cases or exclusions.

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