apply_pixel_outline

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

With no annotations, the description carries the full behavioral disclosure burden, but it only says 'Add a deterministic pixel outline.' It does not disclose whether the tool writes to output_filename, modifies inputs, handles transparency/alpha, or what happens with formats, thickness, or missing colors. 'Deterministic' is a small transparency gain, but significant behavioral context is absent.

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, front-loaded sentence with no filler. It conveys the core behavior and a key property ('deterministic') in minimal space, which is appropriate for conciseness even though more detail is needed elsewhere.

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 5 parameters, no output schema, no annotations, and 0% schema coverage, this description is too sparse for an agent to confidently invoke the tool. It omits which fields are required, how thickness interacts with the outline, what format defaults to, and what the result looks like. The moderate complexity of the tool demands more operational context than one sentence provides.

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 adds no meaning for any of the 5 parameters. It does not mention color, thickness, format, or how input_filename/output_filename relate to the operation. The schema provides structural constraints, but the description fails to compensate for the complete absence of parameter-level guidance.

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 states a specific verb ('Add') and resource ('pixel outline around opaque sprite edges'), and 'deterministic' adds useful precision. It does not explicitly distinguish itself from closely related siblings like outline_native or apply_convolution, but the phrase 'opaque sprite edges' gives enough scope for a clear purpose.

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 is provided for when to use this tool versus alternatives such as outline_native, generate_sprite_shadow, or apply_convolution. The description does not state any exclusions, prerequisites, or conditions that would help an agent choose this tool over its siblings.

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