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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the safety profile is covered. The description adds genuinely useful behavioral context beyond the annotations: no wallet, no payment, no arguments, and that the output is a sample rather than live data. It stops short of describing the payload shape itself.

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 tight sentences, front-loaded with the [FREE] marker and the key constraint (no wallet, no payment, no arguments). Nothing is wasted and the most decision-relevant fact leads.

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-param preview with rich annotations and no output schema, the description covers cost, authentication, and the sample nature adequately. It could say what the preview actually contains (headlines) to be fully self-sufficient, but the title supplies that.

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?

The schema has zero parameters, so per the baseline this dimension is rated 4. The description reinforces this by stating 'no arguments needed', which is consistent with 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 names the parent tool (crypto_news) and states this is a free sample of its response, so an agent can tell it apart from the paid sibling. It is clear enough about what it returns, though the actual content (headline feed) is only conveyed via the title rather than spelled out in the body.

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 a clear condition for use: 'see the shape before paying 0.001 USDC', implicitly routing the agent to crypto_news for the real data. It does not explicitly state when not to use it, but the pricing/model context makes the selection obvious.

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