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

Annotations already cover read-only/open-world/idempotency, and the description adds genuinely non-schema context: pricing ($0.01 USDC via x402 or prepaid credits), no API keys required, free-trial availability, and the de-duplicated/sorted merge behavior. It stops short of describing pagination or failure modes.

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?

Dense but well front-loaded: the core capability leads, then output shape, then alternative, then pricing. Every sentence carries information, though the pricing/credits clause is packed tightly.

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 100% schema coverage and an output schema present, the description does not need to explain parameters or return values; it appropriately focuses on capability, routing and cost. Minor gaps remain around result limits/pagination and the paid-vs-trial distinction.

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 all four parameters (q, days, limit, sources) are already documented with ranges and defaults in the schema. The description only echoes the source list and adds no format or constraint detail beyond it, so the 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?

States a specific verb ('research any topic') and the exact resources covered (Hacker News, Reddit, GDELT, outlet headlines), plus the merge/de-dup/newest-first behavior. It also differentiates itself from the sibling news-brief by routing summary requests elsewhere.

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 ('For an AI-written summary with citations use /news/brief'), which is a clear routing condition. There is no explicit 'when not to use' or guidance on the free trial vs paid path beyond the pricing note.

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