mirror_layer

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

With no annotations, the description carries the burden. It explains the parameters and the effect (mirroring one half onto the other), implying it modifies the layer in place. However, it does not explicitly state if the operation is destructive, required permissions, or error conditions. This is adequate but not fully transparent.

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 concise (4 sentences) with a clear lead sentence and a structured Args section. It is front-loaded with the purpose. Minor improvement could condense the Args into a more compact format, but overall it is efficient and 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?

Given 6 parameters, no output schema, and no annotations, the description is incomplete. It explains only 3 non-required parameters (direction, source_side, axis) but fails to mention the required parameters (filename, layer) and the optional frame. This leaves the agent without guidance for important inputs.

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%, so the description must explain parameters. It details direction, source_side, and axis with acceptable values and defaults, adding significant meaning beyond the schema. However, it omits filename, layer, and frame, which are required or have defaults. This adds value but leaves a gap for key parameters.

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 purpose: 'Mirror one half of a layer onto the other (build symmetric artwork).' This is a specific verb+resource that distinguishes it from siblings like flip_sprite (flips entire sprite) or draw_symmetric_pixels (drawing symmetrically).

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?

No guidance on when to use this tool versus alternatives. The description does not mention any context, prerequisites, or comparisons to sibling tools, leaving the agent to infer usage.

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