capture

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

With no annotations, the description carries full burden but only says 'capture', which is essentially the tool's name. It does not disclose whether the operation is read-only, what happens if the window is not found, or the return format/side effects. The schema descriptions provide some behavioral details, but the description itself adds no safety or failure context.

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 two sentences, front-loaded with the core purpose and followed by an important usage tip. Every word earns its place, with no redundancy or filler.

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 tool has 10 parameters and no output schema, so the description should explain the return value and any nuances like screen mode. The schema covers parameter semantics well, but the description omits the output format (base64 image) and screen capture behavior. It is adequate for basic use but incomplete for full understanding.

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 all 10 parameters, so the schema fully documents each parameter. The description only repeats window_title and process_name without adding new meaning, thus meeting the baseline but not exceeding it.

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 clearly states the tool captures a screenshot of a window by title or app name, using a specific verb and resource. It does not explicitly differentiate from sibling tools like 'see' or 'query', but the action is unambiguous.

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 description provides clear usage context: it explains how to capture a specific window (by title or process name) and that omitting both captures the foreground window. However, it does not mention when to use this tool versus alternatives or mention screen capture mode.

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