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

Annotations only give readOnlyHint=false and destructiveHint=false, so the description carries most of the burden. It does add real behavioral context beyond the annotations: the zone excludes other users from building, painting, or placing objects, and remove_object deletes it. It still omits what happens with overlapping zones, permissions required, or whether the zone can be edited later.

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?

It is short, but brevity here comes from omission rather than economy. The leading clause leans on an undefined 'it' and the sentence fragments are not front-loaded with the actual action, forcing the reader to reconstruct meaning.

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 5-parameter mutating tool with no output schema, the description leaves too much unresolved: what a zone actually is, its persistence, cost/limits, and overlap behavior. The keep_for semantics and the removal path are covered, but the core concept and constraints are not.

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 60%; rows/columns/layers already document the '[from, to], or [one]' format. The description usefully explains keep_for (a person's name) and its '*' default meaning 'you alone', which the schema leaves undocumented, but the 'name' parameter is unexplained in both places, so it only partially compensates.

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 name is add_zone, but the description never says it creates a zone or protected region. It speaks of 'keeps a box of it' with no clear referent for 'it', so an agent cannot tell what resource is being created. It gestures at the concept without stating it, landing closer to tautology than a specific verb+resource.

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?

The phrase 'In your own room' gives a loose precondition, and it names remove_object as the undo path. But it never states when to use this instead of siblings like change_room_settings, place_blocks, or paint_faces, so selection guidance is essentially absent.

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