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

With no annotations supplied, the description carries the full burden and does well: it discloses the paid nature and cost ($0.005 USDC on Base or Solana via x402), the CC BY-SA attribution obligation, the fuzzy-match fallback ('Best title match if not exact'), and the return payload. It omits what happens when no article exists and whether lookups are rate-limited, so it stops short of a 5.

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 Input/Output/Example/Price structure is front-loaded and scannable, with no filler prose. The field enumeration is dense but each item earns its place by telling the agent what it will receive; only the trailing price sentence feels appended rather than integrated.

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?

For a two-parameter lookup with no output schema and no annotations, the description covers the important unknowns: output shape, licensing, payment mechanism, and match behavior. The main remaining gap is failure handling on no-match or invalid lang codes, which an agent would want before relying on it in a pipeline.

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 description coverage is 100%, so both parameters are already documented as strings with the default lang value and example codes. The description restates q as 'topic or title' and gives a worked example (?q=Seoul&lang=en) but adds no new semantics such as what happens with ambiguous or disambiguated titles across languages. Baseline 3 applies when the schema does the heavy lifting.

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?

The description states a specific verb+resource: a Wikipedia/Wikidata lookup returning a cited fact sheet for a place, organization, thing, or concept, and it enumerates exactly what comes back (title, extract, coordinates, thumbnail, Wikidata facts). An agent can tell this apart from generic web tools by the Wikipedia/Wikidata sourcing, though it never explicitly names the alternative siblings (web_answer, web_search, site_profile) it should be preferred over.

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?

It opens with an explicit trigger, 'Use when an agent needs a quick, cited fact sheet on a place, organization, thing or concept,' which is clear context for invocation. It gives no exclusions or named alternatives, so an agent must infer when web_search or web_answer would be the better choice.

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