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

Annotations already declare readOnly=false, idempotent=true, and destructive=false, so the safety profile is covered. The description adds one genuinely useful trait beyond that: the operation replaces the *complete* order rather than adjusting it incrementally. It does not address what happens to columns omitted from the list, or how expectedRevision conflicts are surfaced.

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 front-loaded sentence with no filler. The full-replacement semantics, which is the most decision-relevant fact, comes first.

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 no coverage, and the schema itself documents the idempotency key in detail. Still, for a mutation carrying a required concurrency token and a 1-250 item list, the description omits conflict/retry behavior and the consequence of a partial column list.

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 25% (only idempotencyKey is documented), so the description must compensate. 'Supplied ordered column IDs' adds the critical ordering semantics for columnIds, and 'complete' hints the list must be exhaustive, but expectedRevision is nowhere explained and whether omission deletes a column stays ambiguous.

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 (replace/reorder) and resource (a sheet's complete column order), which distinguishes it from sibling mutations like sheets_move_rows and sheets_reorder_views. It does not name a sibling explicitly, but the scope is unambiguous.

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?

No when-to-use guidance, no prerequisites, and no mention of alternatives such as sheets_move_rows for partial reordering or sheets_reorder_views for the analogous view operation. The agent must infer usage entirely from the name.

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