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

Annotations already declare the safety profile (destructive, idempotent, not read-only), yet the description adds genuinely new operational facts: the 100-item cap, that each item is processed independently so one failure does not affect others, that per-item results are returned, and that {resource}:write scope is required. This is exactly the beyond-annotation disclosure that earns a top score.

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?

Five short, front-loaded sentences ordered from purpose to limits to failure semantics to permissions to rate limiting. Each sentence carries a distinct operational fact with no filler or repetition.

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?

With no output schema, the description usefully states that per-item results are returned, and it covers limits, auth scope, and failure isolation. The one residual gap is the shape of the per-item payload — since items use additionalProperties, the description never notes that updatable fields depend on the chosen resource type.

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 100% for both parameters, so the baseline is 3. The description repeats the item contract ("Each item must include an 'id' field (UUID)") which is already stated verbatim in the items schema, and adds no new syntax or constraint information about the resource enum.

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 with scope: "Update multiple records of a resource type in one API call (max 100)." The batch nature and the resource-agnostic "resource type" framing clearly distinguish it from the single-record update_* siblings and from bulk_create.

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?

Provides clear context for when this tool is worthwhile: it handles up to 100 records and "Counts as 1 request for rate limiting," which implicitly motivates choosing it over repeated single-record updates. It stops short of naming the alternative (update_<resource>) or an explicit when-not condition, so it is clear but not fully routing.

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