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

Goes well past the readOnly/openWorld annotations: discloses the 503 behavior when GDELT is rate-limited or slow, the fallback API, the coverage limitation, and full pricing terms including which payment rails are accepted and that failed calls aren't charged. This is exactly the context an agent needs before spending money on a call.

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 what the tool returns and how, then limitations, then cost — a sensible order. It is dense but nearly every clause carries information; the pricing/payment sentence is the only part that could be trimmed for some audiences.

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 paid, rate-limited, open-world search tool the description covers the gaps that matter: recency, coverage caveats, failure mode, cost and payment. An output schema exists, so listing return fields is supplementary rather than required.

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%, so the schema carries the basics and baseline is 3. The description adds real value by showing GDELT query syntax ("exact phrase", sourcelang:english, domain:bbc.co.uk) for the q parameter, which the schema does not.

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 and resource ('Recent news articles ... that match a query'), scopes it to the last ~72 hours and names the exact upstream source (GDELT Context 2.0 with DOC 2.0 fallback). That scope immediately separates it from sibling news tools like search_google_news or search_bbc_news_articles.

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 72-hour recency window and 'covers the sources GDELT monitors, not every outlet' give clear context for choosing this over other news search siblings. It stops short of naming a specific alternative to use instead, so routing is inferential rather than explicit.

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