art.canvas.set_pixel

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

No annotations are provided, so the description bears the full responsibility for behavioral disclosure. It states only the basic action ('set') and does not mention overwriting behavior, coordinate bounds, session prerequisites, or any failure modes. While 'set' hints at mutation, the description does not explicitly confirm that or any consequential side effects.

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?

A single sentence of eight words that is front-loaded and contains no filler. Every word earns its place, and the size is perfectly proportional to 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 simple tool, this is minimally viable but has gaps. The absence of an output schema means the description should indicate whether the call returns anything meaningful, yet it doesn't. It also fails to clarify that a valid session must exist before use, leaving an implicit prerequisite for an AI to guess.

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% — all four parameters (x, y, color, session_id) have descriptions in the schema, so the baseline is 3. The description adds no further parameter semantics, but since the schema already covers them at a functional level, no deduction is warranted.

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 clear verb ('Set'), a specific resource ('a single pixel'), and immediately delineates this from sibling canvas tools like draw_rect, draw_line, fill, or batch_draw. An agent can unambiguously identify the tool's exact scope without opening the schema.

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 provides no guidance on when to use set_pixel versus alternatives such as art.canvas.batch_draw for multiple pixels or art.canvas.fill for regions. There is no mention of use cases, exclusions, or conditions selecting this tool, leaving the agent to guess the appropriate context.

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