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

The annotations already declare readOnly/idempotent/non-destructive, yet the description still adds meaningful behavior: expectations originate from the checker rather than the caller (tamper-resistance), nothing is persisted, and a passing run grants no execution authority. That is genuine value beyond the annotation set, though it does not mention the 50-case cap or any performance/latency characteristics.

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?

Dense but front-loaded: the core action and output artifacts come first, followed by security-relevant caveats. No filler sentences, though the middle sentence packs a lot of clauses into one line.

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 correctly describes both returned artifacts (the JSON regression and the node:test file) and their contents. The remaining gap is parameter-level detail for a 7-parameter nested schema with a oneOf constraint.

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%, so the description has to carry the burden, and it only partly does — it explains 'caller-supplied records' and each reply's expected verdict, which maps to the record/reply/cases parameters. It says nothing about policy, title, verify, version, or the oneOf exclusivity between reply and cases, leaving several parameters undocumented.

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 names a concrete action (run policy_check on supplied records and export the result as a curbi.regression artifact plus a node:test replay file), a specific verb and a specific pair of resources. It is clearly distinguishable from the policy_check sibling, which just checks one record rather than producing a regression bundle.

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 states a constraint ('no receipts or required-signature mode') and implies the tool is for CI regression generation, which helps. But it never explicitly says when to call this versus policy_check or validate_policy, and there are no exclusions or prerequisites spelled out.

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