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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely new behavior: authentication requirement, account entitlement enforced by OilPriceAPI, unavailability of Permian basin counts and prior-report changes, and a prohibition on substituting US totals. It adds nothing about rate limits or response shape, but the data-availability caveats are exactly the kind of context annotations cannot convey.

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?

Four short sentences with no filler, and the read intent plus geography scope are front-loaded. A couple of the imperatives ('Preserve report dates and geography') read as output-handling instructions rather than tool behavior, which slightly blurs the structure.

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 single-parameter read tool with annotations covering the safety profile, the definition covers auth, entitlement and data caveats well. However, no output schema exists and the description never indicates what 'drilling intelligence' contains (rig counts, wells, permits), leaving return-shape expectations unset.

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?

There is one parameter with 0% schema description coverage, so the description must compensate. It does add real meaning for the 'Permian' enum value by warning that basin counts are unavailable unless explicitly supplied, but it contributes nothing about 'US', 'Canada' or 'international' beyond calling them 'supported'.

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 verb and resource: 'Read authenticated drilling intelligence for a supported geography.' That is clearer than the title alone and separates it from price/history/futures siblings by naming drilling activity as the subject. It never names a sibling to differentiate from, though, so it stops short of a 5.

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?

The scoping constraint ('for a supported geography') and the caveat about Permian basin counts imply when this tool is appropriate, and the 'do not substitute US totals' line is a useful guard against misuse. There is no explicit statement of when to use this versus energy_get_latest or energy_history, so guidance is only implied.

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