set_trigger_sphere_radius

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

Annotations already declare write/destructive/idempotent/false open-world, so the bar is lower. The description nevertheless adds real behavioral context: setting the radius also updates overlaps, the level becomes dirty but is not persisted (the caller must save), and the radius must be > 0. It does not contradict the destructiveHint, since resizing replaces the prior collision radius.

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 result shape and the dirty-not-saved side effect are front-loaded in the first sentence, which is the right priority. It wastes some space by stating the return fields twice (prose then the 'Returns: {...}' block) and repeating the radius>0 rule already in the schema.

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?

No output schema exists, but the description compensates by enumerating the returned fields (actor_name, component_name, previous_radius, new_radius, changed) and the single validation rule. Remaining gaps are minor, e.g. what happens if the named actor is not a TriggerSphere.

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% and both parameters are documented there, including 'unscaled sphere radius in cm, greater than 0'. The description restates the radius constraint and adds nothing about actor_name resolution beyond what the schema already says, so 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?

States a specific verb ('Resize') and a specific resource ('a TriggerSphere ... sphere collision component'), with precise scope ('unscaled radius', 'in the editor world'). An agent can tell it acts on sphere triggers, though the description never explicitly contrasts it with the box-trigger sibling set_trigger_box_extent, so differentiation is only implicit.

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 implied rather than stated: it applies to a TriggerSphere already placed in the editor world and warns that the level is marked dirty, not saved. There is no explicit when-to-use/when-not or pointer to the alternative tool for box triggers or for reading overlap state (get_trigger_info / get_trigger_overlap_count).

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