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

With no annotations, the description carries the full burden and does so: merge/last-write-wins semantics, a 500-row cap, all-or-nothing atomicity with the exact failure trigger (missing id or cross-workspace id), safe-resend guidance on error, type coercion, and the return shape. This is unusually complete behavioral disclosure.

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?

Opens with the verb+resource and the sibling comparison, then layers payload shape, merge rules, limits, and failure semantics. Every sentence carries a distinct behavioral fact; there is no filler or restatement of the name.

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?

Despite having no output schema, the description names the return value (`{ updated, rows }`) and covers atomicity, limits, coercion, and error recovery. For a 2-parameter bulk-mutation tool with no annotations, nothing an agent needs to call it correctly is missing.

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 the baseline is 3, but the description goes further by explaining the merge semantics of `data` (only send changed cells, last-write-wins per field), the provenance of `id` (from list_rows / get_row), and the 1-500 range. It adds genuine meaning beyond the schema's field descriptions.

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 ('Update many existing rows') and explicitly positions itself as 'the bulk version of update_row', which cleanly separates it from both update_row and bulk_create_rows in the sibling list. An agent can pick it without opening either schema.

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?

Gives an explicit selection rule: use this instead of looping update_row when changing more than a few rows, and cites the reason (lower latency and token cost). The named alternative and the threshold condition make the choice unambiguous.

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