Point: Snap (deterministic OSNAP)

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

Description adds 'deterministic' property and emphasizes error elimination, beyond the readOnlyHint annotation. Consistent with annotations, no contradiction.

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 sentences, no filler. Front-loaded with purpose, then usage guidance. Each sentence earns its place.

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?

Covers core behavior, usage intent, and leverages annotations for read-only. Output schema exists so return values are documented. Slight gap: no mention that entity must exist, but schema makes handle required.

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 100%, so baseline is 3. The description does not add new parameter context beyond what the schema already provides (snap types, ref_x/ref_y usage).

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 computes a deterministic snap point on an entity, distinguishing it from coordinate guessing and from other point tools like point_intersection or point_tangent.

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?

Explicitly says to use 'INSTEAD OF guessing coordinates', providing clear when-to-use guidance. Does not mention when not to use or contrast with sibling point tools, but the context is clear.

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