spawn_navmesh_bounds_volume

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

With annotations only stating readOnly=false, destructive=false and non-idempotent, the description carries the interesting behavior itself: that an empty brush yields 0 navmesh tiles, that a REAL cube brush is built, and that brush data is re-read off the spawned actor rather than trusted from the payload. It does not discuss undo, editor-world requirements, or permissions, so it stops short of a 5.

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?

Purpose is front-loaded in the first sentence and the mechanism explanation earns its place. The extensive 'Returns' enumeration is bulky, but with no output schema it is doing necessary work; the ALL-CAPS emphasis (REAL, RE-READ) adds mild noise.

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 world-mutating spawn tool with no output schema, the description compensates by enumerating the return payload and explaining the brush-validation semantics. It still omits where the volume lands (current level), whether an editor world is required, and persistence/undo behavior, so not fully complete.

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%: the schema already fully explains that extent is a semi-extent in cm with a concrete 2x example, and that location defaults to origin. The description adds nothing beyond restating 'specified location with optional extent', so the baseline 3 applies.

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 opening sentence gives a specific verb (spawns) and resource (navigation mesh bounds volume) plus the key qualifier that it builds a real cube brush so nav bounds are non-empty. The name and description are unambiguous against siblings such as spawn_nav_modifier_volume and spawn_nav_link_proxy, which target different volume types.

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?

Usage is only implied: the note that no hand placement in the editor UI is required suggests programmatic creation, but there is no explicit when-to-use or when-not-to-use guidance. It never mentions follow-up tools like rebuild_navigation, nor when to prefer this over rebuilding or manually placing a volume.

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