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

Beyond the annotations' read-only/open-world safety profile, it discloses latency (3-7 seconds), the x402 paid-per-call model, and the failure semantics ('if nothing recent is found the call fails and is not charged'). It also bounds output to what dated results support. Rich behavioral context an agent cannot get from structured fields.

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 dense paragraph that front-loads the return shape and core purpose, then layers constraints, alternatives, and cost. Every sentence carries load, though the inline schema sketch makes the sentence long and slightly harder to scan.

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?

Covers return shape, result count, ordering, latency, pricing, failure behavior, and parameter tuning. An output schema exists, yet the description still adds the interpretive details an agent needs before committing a paid call. Nothing material 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?

Schema coverage is 100%, so the baseline is 3, but the description adds genuine meaning: q should be a short topic/name rather than a full question, and days is a look-back from today (1-30, default 7) that must be raised for quiet topics. This is more than a restatement of the 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?

States a specific verb and resource ('Returns recent news on one topic, person, company or event') and immediately distinguishes itself from web.search for raw links. An agent can pick it apart from the research.* and web.search siblings without inspecting schemas.

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?

Gives an explicit alternative ('Use web.search for raw links'), query-shaping advice ('a short topic or name works better than a full question'), and parameter tuning guidance ('a quiet topic needs a larger value'). Both when-to-use and how-to-use are covered.

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