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

Annotations declare readOnlyHint=false and openWorldHint=true, but the description adds crucial behavioral context: the operation is synchronous and free, modern manifest revisions are never re-sliced, legacy paths retain source-sheet re-cutting, fitItemIndices is one-shot, omitted fields preserve current values, and cellOffsets:[]/cellInset:0 clear values. It also tells the agent to call get_asset afterwards. This goes well beyond the annotations and makes the side effects and return behavior clear.

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 dense but every sentence earns its place: sync/free status, main operation, per-revision path differences, legacy prerequisites, field semantics, clearing semantics, and follow-up call. The most important operational facts (FREE, SYNCHRONOUS, no polling) are front-loaded. It is long, but the tool has real complexity to convey.

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 6-parameter synchronous tool with no output schema, the description covers the operation, the revision-dependent behaviors, the legacy upgrade prerequisite, clearing semantics, and the recommended follow-up call. There is no obvious missing piece an agent would need to safely invoke it or interpret the flow.

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%, so params are already documented. The description adds meaning beyond the schema by explaining how parameters interact: anchor chooses the shared fixed point, cellOffsets apply per-item nudges, cellInset removes legacy separator bleed, fitItemIndices makes items fill their shared cell while preserving aspect ratio, and omitted fields keep current values. It doesn't enumerate every enum value, but the schema already does that.

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 verb+resource: 'Rebuild a staged, tileset, or terrain collection's presentation layout', and clearly differentiates itself from siblings like animate_asset, fix_asset_seams, or revise_asset by describing the layout/arrangement operation. It names the key dimensions (anchor, cellOffsets, cellInset, fitItemIndices) and distinguishes modern manifest revisions from legacy revisions, so an agent can identify the tool's unique role.

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 description gives explicit when-to-use guidance: 'FREE and SYNCHRONOUS (no jobId — do not poll)', 'Legacy terrain must be upgraded to independent items first', and 'call get_asset afterwards for fresh presigned tile URLs'. It also states what not to expect (no AI) and how to clear fields, leaving little ambiguity about when this tool is appropriate.

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