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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds two things annotations cannot convey: the result shape (27 fields including applicable_fraction and applicable_jurisdictions) and a concrete price of $1.25 USDC, a material cost signal for an agent.

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?

Every element earns its place — the only objection is ordering and grammar: it opens with a sentence fragment, then a run-on sentence with a comma splice before the return shape and price. It is compact but not well-structured or front-loaded.

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?

An output schema exists and annotations are rich, so the description needn't explain returns or safety. But for a tool whose whole premise is resolving 'regimes' from an opaque `facts` object, the description gives no sense of what facts must be supplied, leaving the caller to infer from boilerplate schema text.

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 `facts` and `subject_id` are structurally documented, which sets the baseline at 3. However, the schema text is boilerplate ("The facts this operation operates on"), and the description adds no meaning of its own for either parameter, so no credit above baseline.

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 tool's job comes across as determining which jurisdictions/regimes apply, and it explicitly contrasts itself with `create_signed_data_snapshot`. The phrase "Resolve which regimes attach" is jargon-heavy and would be vague on its own, but the sibling contrast plus the mention of applicable_jurisdictions fields makes the intent recoverable.

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 names an explicit alternative and the condition that selects it: use this rather than `create_signed_data_snapshot` when the goal is jurisdictions, not signed snapshots. That is real routing guidance, though there is no guidance on when not to use this tool at all or any prerequisites.

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