mgba_screenshot

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

With no annotations provided, the description fully discloses behavioral traits: 'DESTRUCTIVE TO TARGET FILE if `path` is supplied: overwrites the file at `path` if it exists, with no prompt or backup.' It also covers error conditions (missing parent directory, missing method), meeting the full burden.

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 well-structured with clear sections (PURPOSE, USAGE, BEHAVIOR, RETURNS). Every sentence provides essential information without redundancy. It is appropriately sized for the tool's simplicity.

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 single-parameter tool with no output schema, the description covers all needed context: purpose, when to use, behavior including side effects, error conditions, and return format. No gaps remain.

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 100% for the single parameter. The description adds value by explaining the behavior when omitted ('omit to let mGBA pick a filename in its default screenshot directory and return that path'), which is not inferred from the schema alone. This goes beyond the baseline of 3.

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 explicitly states 'Save a PNG screenshot of the current emulator display to a file.' It clearly identifies the verb 'save' and resource 'screenshot', distinguishing it from sibling tools that perform other operations.

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 usage section provides clear context: 'capture visible game state for inspection, comparison across savestates, or sequence documentation.' It also gives explicit prerequisite steps like 'pause / advance frames / load state first.' However, it does not explicitly state when not to use this tool or list alternative tools, missing a 5.

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