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

Annotations cover the safety profile (write, idempotent, non-destructive, closed-world), so the bar is lower, and the description still adds real behavior: outcomes are revealed only afterwards and are sorted worst misses first, plus the enumerated verdict categories. It doesn't address repeat-submission or resubmission semantics, which matters given idempotentHint=true.

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?

Three short sentences that front-load the action ('Grade your exam answers') before the conditional and the outcome description. No filler, though the middle sentence is slightly compressed for the amount of behavior it carries.

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 carries the burden of describing the return and does so: three verdict values and the worst-misses-first ordering. It leaves gaps on the p-value input semantics and on how this call relates to start_exam, so it isn't fully self-contained for a 4-parameter workflow 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 coverage is 75% and the schema itself documents api_key, incumbent ('Answers from your current rules'), and challenger ('Optional. Answers from the rule change you're testing.'). The description's mention of incumbent/challenger sets mirrors that, but adds no format detail (the p probability meaning, the max-60 item limit, or the requirement that item ids align across sets).

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 gives a specific action (grade/submit exam answers) and resource (blind exam), and pins down the exact output shape: a paired verdict of 'keep the change, not proven yet, or drop it'. It uses the same incumbent/challenger vocabulary as the schema, so an agent can map inputs to outcome. It never names the sibling start_exam, so the lifecycle stage isn't explicitly differentiated.

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?

Usage is only implied: providing a challenger set yields a paired verdict, omitting it presumably yields a single-set score. That's a useful conditional, but the description never says when to call this versus start_exam or whether a prior exam must exist, and it gives no prerequisites or exclusions.

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