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 genuine context beyond that: 'Keyless' (no auth required) and what the response contains (earliest/latest reported month). It stops short of rate limits or result-size notes, so it lands just under the top.

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?

Front-loads purpose, then usage in a compact sentence, then two concrete call examples. The examples are useful rather than padding, though the sentence is slightly long; almost every element earns its place.

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 simple keyless list tool with no output schema, the description is nearly complete: it explains purpose, usage, return contents, auth, and gives examples. A minor omission is any note on result size or pagination, but nothing an agent needs to call it correctly is missing.

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% and the single 'commodity' parameter is already documented as 'oil', 'gas', or omit for both. The description's examples reinforce usage of the param but add no syntax or constraint detail beyond the schema, so the baseline 3 applies.

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?

States a specific verb (List) and resource (countries JODI-Oil/Gas cover) plus a scope detail (earliest/latest reported month). It clearly distinguishes itself from jodi_oil_series and jodi_gas_series, which return series rather than coverage metadata.

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?

Explicitly says to use it 'before jodi_oil_series/jodi_gas_series to confirm a country actually reports the commodity', naming the alternative tools and the condition that selects this one. Also enumerates the exact questions it answers (coverage lists, does JODI have Iran gas data).

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