draw_line

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

Annotations already declare readOnlyHint=false and destructiveHint=true, so the mutation profile is covered. The description adds genuinely new behavioral context: the operation is undoable with Ctrl+Z, and omitting layer falls back to the active layer. Those are real traits beyond the structured data.

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?

Front-loaded purpose, then a when-to-use block, then parameters, then a concrete example — a clean, scannable structure. It is slightly label-dense and the example could be tighter, but no sentence is wasted.

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?

Output schema exists, so return values need no explanation, and the description covers purpose, usage, parameter formats, layer preconditions and undo behavior. It does not state what happens if the named layer is missing, which is the only material gap.

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%, so the description carries the full burden and does so: start/end accept [x, y] or [x, y, z] in drawing units, and layer must be an existing layer and is optional with a documented active-layer default. All three parameters gain meaning absent from the schema.

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 resource ("Desenha uma linha no espaço modelo") and scopes it to axes, references and simple traces, which implicitly separates it from draw_polyline. The scope note does the work of differentiation without naming the sibling explicitly, so it falls just short of a 5.

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?

A dedicated "QUANDO USAR" line tells the agent when this tool fits (axes, references, simple geometry) and, by contrast, when a more complex primitive is warranted. It stops short of naming the alternative tools or stating exclusions outright, so a 4 rather than a 5.

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