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

With no annotations, the description carries the full behavioral burden, and it does disclose the credit cost and the shape of the returned data, which is real value. It says nothing about behavior on a missing/ambiguous title, language fallback, or truncation of the lead summary, which are the main failure modes an agent would want to know about.

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 compact sentence with zero filler, front-loading the return contents and appending the cost note where it is easy to scan. Slightly weakened by leading with output fields rather than the action itself.

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 simple two-parameter lookup tool this covers the essentials, and listing the returned fields compensates for the absent output schema. It remains thin on lookup failure behavior and on selection versus sibling tools, which is what an agent would most need beyond the schema.

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% and both parameters are documented in-schema (two-letter lang code defaulting to 'en', title required). The description adds no additional meaning about title format such as page title vs. free text or disambiguation handling, so the baseline 3 applies.

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 names a specific resource (a Wikipedia article) and enumerates exactly what it returns: lead summary, description, coordinates and Wikidata id. However, the verb is implicit (no 'get'/'fetch'), and it does not explicitly distinguish itself from the nearby wikidata_lookup sibling, which overlaps on the Wikidata id field.

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?

There is no guidance on when to use this versus wikidata_lookup, news_search, or read_url for encyclopedic facts. The only usage-adjacent information is the cost note, which is helpful but is not a when-to-use/exclusion rule.

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