tv_screenshot

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

No annotations are provided, so the description carries the full burden. It discloses the meaningful risk that captureScreenshot can hang or return black on Samsung/Tizen due to the secure video/overlay plane, and clarifies that UI screens are generally safe. This goes well beyond a bare 'take a screenshot' statement, though it could mention error codes or recovery 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?

Two sentences: the first states the action and output; the second delivers the crucial caveat and alternative usage. No filler, information is front-loaded and immediately actionable.

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 tool with no annotations and no output schema, the description is complete: it explains the primary purpose, the failure modes, the safe use cases, and points to an alternative for video playback checks. All parameters are already fully documented in the schema, so no additional param context is necessary.

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%, so the baseline is 3. The description doesn't add extra detail about path, device, or timeout beyond what the schema already provides, but it confirms the tool saves a PNG and gives a sense of intended output.

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 uses a specific verb ('Capture') and clearly identifies the resource ('app frame via CDP') and output (PNG). It also distinguishes itself from the sibling tv_video_state by advising that for playback verdicts, tv_video_state and a human glance are preferred.

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?

Explicitly states when to use the tool ('UI screens, menus, focus, tiles usually capture fine') and when not to ('for playback verdicts prefer tv_video_state and a human glance at the physical TV'). Names the alternative tool and provides contextual reasoning about Samsung/Tizen limitations.

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