set_landscape_spline_control_point

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

Annotations already declare idempotentHint=true and destructiveHint=true, so the safety profile is covered. The description adds real behavioral context beyond that: non-clobbering partial semantics, applied_count reporting, landscape-local (not world) coordinates, and half-width interpretation. It could say more about the destructive/reversibility implications, but it adds solid value.

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 with the core action and a practical framing before the semantics notes. The added Returns block is warranted because no output schema exists, so it isn't waste. Tight overall, though the returns enumeration is slightly verbose.

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?

With no output schema, the description supplies the return shape (applied_count, updated, etc.). For a mutation tool with annotations present, it covers coordinate space, width semantics, partial-update behavior, the prerequisite read tool, and return contents — everything an agent needs to invoke it correctly.

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%, so the baseline is 3. The description goes beyond the schema by flagging that location is LANDSCAPE-LOCAL rather than world and that width is a HALF-width — non-obvious semantic details that prevent unit/space errors. These are meaningful additions on top of the already-rich 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?

The description states a specific verb set (move, rotate, re-width) applied to a precise resource (one existing landscape spline control point by index), and clarifies intent with 'how you adjust a road or river route without rebuilding the spline.' This cleanly distinguishes it from siblings like add_landscape_spline_control_point and remove_landscape_spline_control_point.

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?

It gives clear context and a concrete precondition: 'Read the current values first with get_landscape_spline_control_point,' naming the complementary tool. It also states partial-update behavior ('Only the fields you pass change'). It stops short of explicit when-not-to-use or alternative-tool routing, so it isn't a full 5.

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