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

Annotations already establish readOnly, idempotent, non-destructive, closed-world behavior. The description adds genuinely new context: results are individual claims each carrying a publisher, so figures can be checked and cited, which tells the agent about granularity and provenance of results.

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-loaded with the trigger condition ('Use this when...'), followed by scope, result nature, and exclusion. Three sentences, all earning their place, no redundancy.

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 an output schema present, return formatting need not be explained, and annotations cover the safety profile. The description covers trigger, scope, and result granularity well; only minor operational details (result limits, pagination, how multiple minerals combine with query) are unaddressed.

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%, so both the free-text query and the mineral slug are already documented in the schema with matching examples. The description adds no new syntax, matching behavior, or filter-combination guidance beyond what the schema provides.

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 (search) and resource (individual sourced claims in the evidence base) and enumerates the exact topical domains (production, processing/refining capacity, export controls, country concentration). This is clearly distinguishable from siblings like get_commodity_snapshot or search_trade_flows.

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?

Gives explicit when-to-use with three concrete example queries and a clear when-not ('Do not use for live prices or investment advice'). It does not name the sibling tools that should be used instead, so the routing is implied rather than explicit.

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