pix_save_screenshot

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

Annotations already signal that this is not read-only, is idempotent, and is non-destructive. The description adds that it writes a PNG screenshot of a capture frame, but it does not disclose where the file is written, whether an existing file is overwritten, or whether the capture must be open.

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 a single clear sentence with no filler and the core action is front-loaded. It could be more informative, but as a concise statement it is well structured.

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 four parameters, no parameter descriptions in the schema, and a write side effect, this description is incomplete. The output schema removes the need to explain return values, but destination, refresh behavior, timeout, and any prerequisites are missing.

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?

With 0% schema description coverage, the description needed to explain the four parameters, but only 'capture's frame' hints at capture_id. refresh, destination, and timeout_seconds are left entirely unexplained, so the agent cannot know their semantics without external knowledge.

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 names the exact operation ('Save'), the specific resource ('the capture's frame screenshot'), and the output format ('as a PNG'). This clearly distinguishes it from sibling save tools like pix_save_resource and pix_save_high_frequency_counters.

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?

There is no guidance on when to use this tool versus any alternative, and no mention of required capture state or typical scenarios. The single sentence describes what it does but not why or when an agent should call it.

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