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

Annotations already provide readOnly, idempotent, and openWorld hints, so the bar for extra value is met by the description's explicit disclosure that there is no article text because GDELT indexes metadata only. This prevents an agent from expecting body content or an empty payload, which is genuinely useful beyond the schema.

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 description is compact, front-loaded with the action and return contents, then adds the key caveat about missing article text. Every sentence earns its place and there is no redundant filler.

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 one required parameter, rich annotations, and no output schema, the description fully covers what the caller needs: the input source, the returned metadata fields, and the absence of article text. Nothing required for a correct call 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 parameter description already states the URL should come from china_news_search. The tool description reinforces the exact-URL requirement but does not add substantive semantic detail beyond the schema, so the baseline score of 3 is appropriate.

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 uses a specific verb and resource: 'Look up one indexed China/Hong Kong/Taiwan news article by its URL' and enumerates the exact data returned. It clearly differentiates from china_news_search by focusing on a single article identified by URL rather than a set of search results.

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 instruction 'Pass a url exactly as china_news_search returned it' provides a concrete prerequisite and ties this tool to its sibling search tool. It does not explicitly state when not to use it or name alternatives, but the context makes the intended workflow clear.

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