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

Goes well beyond the annotations: discloses Brave's terms restricting storage, resale and model training, states that upstream failures return 503 uncharged, and gives the price ($0.01/call via x402 USDC or card key) with the note that repeat calls are not free. This complements the readOnlyHint/destructiveHint/idempotentHint annotations rather than repeating them.

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?

The purpose and return shape are front-loaded, and each block (output, limits, licensing, pricing, read-only) earns its place. It is on the dense side with some redundancy between 'crypto included', the title, and the example, but no sentence is filler.

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 fully covers the return shape (title, URL, snippet, publisher domain, age), result-count and freshness bounds, error behavior, cost model, and legal constraints. An agent has everything needed to call it correctly and understand the consequences.

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 three parameters are already documented in the schema, and the description largely restates them ('1-20 results', 'past day, week or month'). The q=bitcoin ETF example is the only added semantic value; the freshness values are not enumerated more precisely than 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 ('search current news on any topic') plus the exact source (Brave Search API's news index) and the returned fields. It is clearly a news search rather than a generic web search, but it never names the sibling `search` tool or any news alternative, so the differentiation is implied rather than explicit.

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 says 'Use when an agent needs current news on a topic' and supplies a concrete example (q=bitcoin ETF), which gives a clear use context. It offers no when-not-to-use condition or named alternative for non-news lookups, so it falls short of a 5.

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