draw_polyline

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

Annotations declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, and openWorldHint=false, so the safety profile is covered. The description adds the genuinely useful 2D-vs-3D behavior (auto-escalates to 3D when Z varies), which is not in the annotations. It does not, however, note that a missing layer is created as a side effect.

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 tight sentence with zero waste, leading with the core action and appending the one non-obvious behavioral detail. Nothing redundant.

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?

An output schema exists, so return values need no explanation. For a 5-parameter drawing tool the description is minimally adequate: it covers the core action and 2D/3D nuance but omits sibling differentiation and side effects (auto layer creation), which an agent would want.

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?

With schema description coverage at 60%, color, layer, linetype, and points items are already documented; only 'closed' is undocumented. The description's '3D if Z varies' adds a small amount of meaning about the points array, but otherwise repeats what the schema conveys. Baseline 3 for partial coverage is appropriate.

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: 'Draw a polyline through the points.' The 2D/3D parenthetical further specifies the operation's nature. It does not explicitly differentiate from siblings like draw_line or draw_polygon, but the multi-point phrasing implicitly distinguishes it.

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?

There is no guidance on when to choose this over the closely related draw_line, draw_polygon, or draw_rectangle siblings, and no stated preconditions. It simply describes what the tool does, leaving routing entirely to inference.

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