Preflight screenshot copy

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

With no annotations, the description carries the full burden. It discloses that the tool rasterizes using the same typography and dimensions as the renderer (simulation), reports measurements, and is non-destructive (before writing). It does not mention failure modes or output format, but the key behavioral traits are 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 a single, dense sentence that front-loads the primary action and key outputs. It is concise and avoids redundancy, though the long sentence could be split for readability.

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 5 parameters, a complex nested schema, no output schema, and no annotations, the description is insufficient. It does not describe the report structure, collision criteria, or parameter semantics, leaving significant gaps for an agent to call it correctly.

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 0%, and the description provides no explanation of parameters like frames, slot, width, height, or locale. The complex nested schema remains entirely undocumented, leaving the agent without guidance on how to construct valid inputs.

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 action ('Rasterize localized screenshot copy'), the specific outputs ('report exact pixel widths and copy-to-source collisions'), and the timing ('before any files are written'). It distinguishes itself from sibling validate_screenshot_set by focusing on copy and collisions, making its purpose 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 implies usage as a preflight check ('before any files are written') but does not explicitly contrast it with validate_screenshot_set or other siblings. There is no when-to-use vs when-not-to-use guidance, leaving the agent to infer the appropriate context.

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