preview_drawing

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description still adds real context: 'ID selection crops the region including nearby context' and 'does not edit or export source' tell the agent how the crop behaves and that source is untouched, which is beyond what the annotations convey.

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?

Two tight sentences with the core fact ('Read-only PNG preview') front-loaded, followed by the option inventory and the two behavioral caveats. No filler or restatement of the tool name.

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?

There is no output schema, but the description names the return format (PNG) and covers the nested options object, so an agent can call it correctly. Minor gaps remain around the required 'name' parameter and dimensions of the returned image, but nothing critical is missing.

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 only 50% and the nested 'options' properties carry no descriptions, so the description does real work by enumerating width/height, absolute crop, ids, padding, background and scaleUp. It also adds meaning the schema lacks ('absolute crop', id-selection includes nearby context), though it omits any note on the required 'name' stem.

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?

States a specific verb and output ('Read-only PNG preview') of a drawing, so an agent immediately knows it produces an image rather than mutating data. It does not, however, name or contrast itself with the sibling it is most likely confused with, export_drawing, leaving sibling differentiation to inference.

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 clause 'it does not edit or export source' implicitly signals when this is preferred over edit_drawing/export_drawing, but it never states the positive condition for choosing preview or any prerequisites. Usage is implied rather than spelled out.

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