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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent mutation, so the safety profile is covered. The description adds useful behavioral constraints (the destination must be a 'compatible visible' folder; null targets the library root), but says nothing about what changes on the sheet, permission needs, or how the declared non-idempotency interacts with the idempotencyKey.

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?

A single sentence that front-loads the primary action and folds the null-edge-case into the same breath. No filler, no redundancy.

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?

An output schema exists, so return values need not be described. For a three-parameter move operation with annotations covering the safety profile and the description covering destination semantics, the essential call information is present.

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 only 33%, so the description must carry weight; it does explain folderId's null semantics (library root destination), which the schema does not. It says nothing about sheetId or the idempotencyKey retry contract, leaving two of three parameters to the schema alone.

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 and resource (move a sheet to a folder) and clarifies the null case as 'move it to its library root'. It is clearly distinct from siblings like sheets_move_rows or sheets_rename_folder, though 'compatible visible folder' is left undefined and no sibling is contrasted.

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 implicitly covers the two usage modes: pass a folder to move into it, or pass null to move to library root. However, it gives no guidance on when a move is appropriate vs. archiving, no exclusions, and no prerequisites (e.g., permission requirements).

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