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

Annotations already cover readOnly, idempotent, openWorld, and non-destructive. The description adds genuinely useful non-schema context: it is free, requires no wallet/payment, and takes no arguments. It stops short of describing the sample payload itself, but the added cost/auth context is real value beyond the annotations.

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?

A single sentence that front-loads the [FREE] preview nature. It is somewhat cluttered by repeating the full tool title in nested parentheses, but there is no wasted exposition.

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 zero-argument preview stub with no output schema, the description says everything needed: what it returns (a sample response), why (see the shape), and the cost/auth model (free, no wallet). Nothing an agent needs in order 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?

Zero parameters, so the schema carries no argument semantics to explain. Baseline is 4 per the rules; the description confirms 'no arguments needed', which matches the empty schema.

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 clearly states this returns a sample response for the paid news_search tool so the agent can preview the output shape. It explicitly names the sibling news_search and the free/paid distinction, but the phrasing is meta rather than a crisp 'returns X' statement, and it leans on the title for the actual subject matter (GDELT, multi-language, tone timeline).

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 gives clear context: this is the free preview to inspect 'before paying 0.009 USDC', with 'No wallet, no payment, no arguments needed'. This tells the agent when to call it (before committing to the paid sibling) though it never explicitly instructs 'use this instead of news_search for testing'.

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