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

Annotations only cover readOnly and openWorld; the description adds substantive traits beyond them — 65+ language coverage, a ~15-minute reindex cadence (i.e. staleness/latency), and the normalized article-list return shape. That is meaningful behavioral context, though permission/auth and result-cap behavior are left to 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?

Two sentences, zero filler: capability and scope come first, the routing caveat second. Everything stated 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 9-parameter read-only search with a full schema and an output schema, the description supplies the missing non-schema context (freshness, language breadth, output shape). Nothing critical is absent, though it could note the absence of pagination beyond maxrecords.

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 every parameter (from/to/timespan/sort/maxrecords/query operators) is already fully documented in the schema. The description only gestures at 'a query and time range' without adding syntax or constraint detail, so 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?

The description gives a specific verb (Search) and resource (the GDELT Project's global news index) plus the key inputs (query, time range), and the 'normalized article list' phrasing signals this is the article-retrieval member of the GDELT family rather than a timeline/tone/tv sibling. It never names gdelt_timeline, gdelt_context, or gdelt_tv_search directly, so sibling routing rests on inference.

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?

It says explicitly what it is good for (worldwide news monitoring) and draws a real exclusion: 'not a live breaking-news feed.' That gives an agent a clear selection context, but no alternative tool is named for the cases this tool is wrong for.

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