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

Adds substantial behavior beyond the annotations: exact pricing ($0.008 USDC via x402 on Base/Solana/Polygon/Arbitrum), the answering model (Claude Haiku 5.5), reading only the top 3 pages, a 7-day news window, refusal behavior when sources don't answer, and no-charge on empty results. This is exactly the operational detail annotations cannot convey.

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?

Front-loads the core purpose and output format before payment and sample details. Although dense, every clause carries decision-relevant information (sources, model, cost, refusal behavior) with no 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 (short answer, numbered [1][2] citations, source list) plus cost, source coverage, freshness window and failure mode. An agent has everything needed to decide and invoke correctly.

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 67%. The description enriches the source enum by explaining what each value routes to (auto prefers news for current events, web = Wikipedia), adding meaning beyond the raw enum. The question and language params are already documented in the schema, so it doesn't need to repeat them.

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 ('Ask a question, get a short answer with numbered citations and the source list') and names its exact search backends (Wikipedia, GDELT/HN, top 3 pages, Claude Haiku). The 'Not a general web index' clause distinguishes it from siblings like web_search and news_search.

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 clear context for choosing a source mode (current events go to news first, web = Wikipedia) and a when-not caveat ('niche or very new topics may have no sources'). It never names an explicit alternative sibling (e.g. web_search) to route away to, so it falls short of a full when/when-not/alternatives statement.

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