line_of_sight

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

The annotations already establish this as a safe, non-destructive read. The description adds important behavior beyond the annotations: object names resolve to bounding-box centres, the two named objects never block the ray, and the result is the first blocker.

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?

The description is front-loaded with the core question, then efficiently adds parameter semantics, ray-blocking behavior, return value, and intended use. Every sentence adds value without repetition.

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?

For a two-parameter visibility query with no output schema, the description supplies the essential input forms, blocking rule, return value, and typical use cases. An agent has enough information 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 description coverage is 0%, so the description must compensate. It does so fully by explaining that each parameter may be a world point or an object name, and that object names use the bounding-box centre.

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 query: whether point or object `a` can see `b`. It clearly describes the resource and operation, but does not explicitly differentiate itself from nearby siblings such as `sightline_map`, `viewshed`, or `raycast`.

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 a clear use context: 'Use it for sight lines, cover and corridors.' However, it does not state when not to use it or which alternative siblings are preferred for related visibility tasks.

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