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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower, yet the description adds real behavioral context: default limit/version, oldest-first ordering, pagination stability ('a version never changes'), the free-tier rate limit (120 pages/hour), egress accounting (50 GB), and paid-dataset price responses. It stops short of describing error or not-found behavior, so it isn't a clean 5.

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?

Front-loaded with the core definition, then defaults, then pagination semantics, then auth/billing, then sibling routing. Each sentence carries distinct, non-redundant information with no padding.

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 compensates by explaining the return shape (total, next, page stability) and covers access/pricing conditions. An agent has everything needed to page through a dataset and understand the paid-dataset exception.

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 adds meaning the schema lacks: the 50-record and latest-version defaults, the oldest-first ordering, and how the response's 'next' offset relates to the offset parameter for pagination.

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 resource and scope: 'a page of the merged records of a dataset version.' It further distinguishes itself from query_dataset (aggregates) and dataset_manifest (whole version), so an agent can route correctly without opening schemas.

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?

Explicit alternatives are named with the condition that selects them: 'For aggregates use query_dataset; for a whole version use dataset_manifest,' plus buy_dataset for paid datasets. Nothing about tool selection is left to inference.

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