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

Beyond the annotations (readOnly/openWorld/idempotent), the description discloses the paid x402 model with a concrete price, the Solana payment rail, an HTTPS fallback endpoint, and the CC BY-SA attribution obligation the agent must surface. These are operationally critical details no structured field carries.

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?

Two front-loaded sentences establish capability and return payload, then a single compact line carries cost and transport. Every clause is load-bearing; nothing is repeated from the name or annotations.

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 takes on the burden of enumerating return fields (title, description, extract, URL, thumbnail, Wikidata id, coordinates, last-modified) plus attribution, so an agent knows exactly what it gets for its $0.005.

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 defaults, ranges, language codes and the title-vs-q distinction are already documented. The description only restates the two modes at a high level and adds no syntax or format detail beyond the schema, matching the baseline 3.

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 first clause names the resource and both modes precisely: keyword search across 340+ language editions returning the top hit's summary, or a direct summary lookup by exact title. No sibling tool covers Wikipedia, so the scope is unambiguous on its own.

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?

The description lays out the two usage modes (query-based search vs. exact-title fetch) and the schema reinforces the choice with 'use instead of q'. It stops short of stating exclusions such as when to prefer web_to_text or wayback for full-page content, but the mode selection is clear.

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