Preview drawing a tile shape

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

Annotations already indicate readOnlyHint=true and destructiveHint=false. The description adds valuable behavioral traits: determinism, no randomness, no clipping (fails closed), at most 10,000 cells, null tile erases, and that preview/revision-pin/transaction rules apply. This significantly informs the agent beyond the annotations.

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 two sentences, front-loaded with the core action in the first sentence and constraints in the second. Every phrase adds value with no redundancy.

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 the tool's complexity (nested draw schema, 6 parameters) and the presence of an output schema, the description covers essential behavioral constraints (determinism, cell limit, null tile) and integrates with the preview workflow. Minor gaps like how to apply the change set are addressed by sibling tools.

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 only 33%, placing the burden on the description. It adds meaning for the tile parameter (null erases) and explains the shape types, but does not detail the draw property's substructures, layerId, mapPath, or revision parameters. Some improvement over the bare schema but incomplete.

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 'rasterizes one deterministic geometric shape' into tile cells and returns a change set. It names specific shapes (Bresenham line, rectangle, ellipse), making the purpose highly specific and distinguishable from sibling preview tools like tiled_preview_edits or tiled_preview_generate.

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 explicit guidance on when to use this tool versus alternatives is provided. The description explains what the tool does but does not contrast it with other preview tools or state prerequisites. Given the large set of sibling preview tools, this omission reduces usability.

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