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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so safety is covered. The description adds genuinely useful context beyond that: ordering (newest first), the archive coverage boundary ('starts when Basis began collecting'), and the warning that an empty page does not prove no news occurred.

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?

Four short, front-loaded sentences with zero filler; the core purpose and the sibling routing come first, and the caveats follow.

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 no output schema, the description does its part by describing the return shape (headlines, newest first, source links, no full article text) and the coverage caveat. It is nearly complete for a read tool; only the parameter-name error in the pagination guidance keeps it from being fully self-sufficient.

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 50% and the description does not fill the gap; instead it refers to pagination via 'nextBefore' while the actual parameter is named 'before', which is actively misleading. It adds no format or usage detail for asset, limit, or topic beyond what the schema already specifies.

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 (read archived crypto headlines) with scope details (newest first, source links) and explicitly distinguishes itself from the sibling news_recent. An agent can pick it apart from news_recent without opening either schema.

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?

Explicitly names the alternative and the selection condition ('Use news_recent for live headlines') and adds a negative use case ('No full article text'). However, the pagination instruction points at 'nextBefore', a parameter that does not exist in the schema, which weakens the otherwise strong routing guidance.

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