get_source_screenshot

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

With no annotations provided, the description carries the burden. It discloses that the tool returns a Base64-encoded screenshot, implying a non-destructive read operation. Parameter constraints (ranges, defaults) add transparency. It doesn't explicitly state non-destructive or error behavior, but the core behavior is well-covered.

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 succinct and well-structured with a brief intro and an Args list. Every sentence adds value, covering purpose, format reference, and parameter details without fluff.

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?

Despite no output schema, the description explains the return format (Base64), all parameters, and cross-references get_version for format validation. It is sufficiently complete for a screenshot tool with 5 parameters and no nested objects.

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 coverage is 0%, but the description explains every parameter in detail: source_name (input or scene), image_format with examples, optional image_width/height with range and omission behavior, and compression quality with range and -1 default. This adds significant meaning beyond the bare schema.

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's function: 'Get a Base64-encoded screenshot of a source (input or scene)'. It specifies the resource (source) and output format (Base64), and distinguishes from sibling tools like save_source_screenshot by emphasizing the encoded return.

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 phrase 'use this to actually SEE what's on stream' provides a clear use case. It also directs users to get_version for valid image_format values, which is helpful. However, it doesn't explicitly mention when not to use it or contrast with save_source_screenshot, though the Base64 return implicitly differentiates it.

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