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

Annotations already declare destructive/idempotent/readOnly, and the description layers on real operational context beyond them: per-item independent processing so one failure does not abort others, per-item results returned, required {resource}:write scope, and single-request rate-limit accounting. This is exactly the extra disclosure expected when annotations set a lower bar.

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 tight sentences, front-loaded with what the tool does (bulk update in one call), then progressively adding constraints, failure semantics, auth, and rate-limit notes. Every sentence carries information an agent needs.

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?

No output schema exists, and the description compensates by disclosing per-item results. Combined with batch size, failure isolation, scope, and rate-limit behavior, an agent has everything required to invoke and reason about the result of this mutation tool.

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%, so the schema already documents both the items array and resource enum. The description restates the id/UUID and max-100 constraints but adds no syntax, format, or field-merge semantics beyond the schema, so baseline 3 applies.

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+resource (update multiple records of a resource type) plus the batch scope (one API call), which cleanly separates it from the many single-record update_* siblings and from bulk_create. An agent can identify it without opening the 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 concrete usage context: max 100 items, items need an id, and it counts as one request for rate limiting, implying it is the efficient path for many updates. It stops short of explicitly saying when to prefer this over the per-resource update_* tools or bulk_create, so it is clear but not fully differential.

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