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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the safety profile is covered by structured data. The description adds that this changes attributes of already-placed items, but does not disclose side effects, whether changes propagate (e.g., a door's destination affecting linked rooms), or any permission requirements. Given annotation coverage, a 3 is appropriate.

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 a single front-loaded sentence with no filler, but the parallel phrasing ("a canvas's, label's or door's look") is dense and hard to parse on one read. The information earns its place, yet the structure sacrifices clarity for compactness.

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 mutation tool with 8 parameters, 13% schema coverage, and no output schema, the description covers parameter semantics well but omits usage context, prerequisites, and behavioral consequences. It is adequate but leaves meaningful gaps an agent would need when deciding to call it.

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 only 13% (just id is documented), so the description must carry the load, and it largely does: it assigns meaning to text, picture, look, destination, arrive_at, keep_for, and name. It does not clarify format expectations (e.g., how destination differs from arrive_at, or id comes from look), but the semantic mapping is a substantial addition over the bare schema.

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 gives a clear verb ("Changes") and, through the enumeration, identifies the resource types being modified: labels, doors, canvases, and zones. The mapping of each editable attribute to its object type makes the tool's scope concrete. It stops short of explicitly distinguishing itself from siblings like move_object or add_object, but the 'edit properties of an existing placed object' purpose is unmistakable.

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?

There is no explicit when-to-use versus alternatives (add_object, move_object, remove_object are never mentioned). The field-to-object-type mapping implies what can be edited and thus when the tool applies, but an agent must infer that this is the mutation counterpart to those siblings. This is implied usage rather than stated guidance.

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