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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is given. The description adds genuinely useful context beyond that: the scope is a single preset (at most six shocks, presumably), the output is a modelled path with a stated counterfactual delta 'from holding current policy', and the explicit caveat that it 'never recommends one' sets interpretive expectations. It does not contradict any annotation.

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 output inventory is front-loaded and useful, but the middle third enumerates preset, shock and demandScenario values that are fully documented in the schema, which is pure duplication. The result is a dense, run-on single sentence that an agent must parse carefully; trimming the enum lists would sharpen it without losing information.

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?

There is no output schema, so the description correctly takes on the burden of describing return values, and it does so thoroughly — time horizons, every headline metric, and the current-policy delta. Combined with fully documented parameters and read-only annotations, an agent has everything needed to call and interpret this 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 description coverage is 100% — every parameter has a description, enum, default and range — so the schema carries the load and baseline 3 applies. The description does helpfully spell out the composite shock family '{iran|russia|venezuela}-{tighten|ease}', which is easier to parse than the flattened enum, but otherwise it repeats the preset and demandScenario values already in the schema rather than adding meaning.

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 opens with a specific verb and resource — 'Runs one preset Saudi production path through the model' — and enumerates the concrete outputs (Brent by month/year, exports, revenue, fiscal balance vs IMF breakeven, market share, spare capacity, NPV, shale response, policy delta). That is far beyond a restatement of the name. It stops short of 5 because it never names or contrasts a sibling such as oil_outlook or oil_balance, so an agent must infer the boundary itself.

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?

'Runs one preset ... path' implies single-scenario use and the closing line 'Modelled scenario analysis under stated assumptions; it describes paths and never recommends one' frames the analytical intent. However there is no explicit when-to-use versus when-to-use-an-alternative statement, and no guidance on which preset a user should pick for a given question.

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