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

The annotations already establish that this is a read-only, idempotent, non-destructive tool. The description adds valuable behavior beyond the annotations: it caps results at 20 rows, notes that coverage varies by dataset, and states that history starts October 3, 2026.

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?

The description is compact and front-loads the key fact that it returns real preview rows capped at 20. Each sentence carries relevant constraint or orientation information, with little wasted text.

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?

For a one-parameter preview tool with no output schema, the description covers the main behavioral facts an agent needs: row limit, supported datasets, history boundary, coverage variability, and the related days_available tool. It does not describe the returned row shape, but that is a minor gap here.

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 0%, but the single dataset parameter has an enum listing graduates, gradtrades, and pregrad. The description repeats those values and notes that coverage varies by dataset, but it does not explain further distinctions among the datasets or add much detail about the parameter beyond the 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?

The description states a concrete outcome: returning real preview rows, capped at 20, for three named datasets. It also references days_available for exported UTC day ranges, which helps distinguish this preview tool from a date-range utility, though it does not define itself against the other data-query siblings.

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?

It gives useful constraints, namely that only graduates, gradtrades, and pregrad have site previews and that days_available should be used for exported UTC day ranges. However, it does not explicitly say when to choose data_preview over other data-oriented siblings such as day_full_stats or graduation_stats.

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