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

With no annotations supplied, the description carries the full load and does add real behavior: the response path query.pages[].extract, the licensing/attribution obligation when displaying content, and that the call consumes OpenAny gateway credentials with gateway-determined charges and authorization. It does not describe what happens for a missing title or a disambiguation page, and gives no rate-limit or failure signal, which keeps it 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?

Three short sentences, each doing distinct work: what is returned, where it lands in the response plus the attribution requirement, and the credential/billing model. The core capability is front-loaded in the first clause with no filler or restatement of the title.

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 nine-parameter, fully required, fully enumerated read tool with no output schema, the description covers return shape, display obligations, and billing model adequately. What is missing is edge-case behavior (title not found, redirect resolution outcomes), which an agent would need 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% and seven of nine parameters are fixed enums, so the schema already documents titles, excchars, and the constant flags. The description adds only the high-level framing ('short', 'plain-text', 'introduction'), which loosely maps to excchars and explaintext but adds no syntax or format detail beyond what the schema states; 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?

States a specific verb and resource ('Retrieve a short plain-text introduction'), names the language edition (Chinese Wikipedia), and scopes the result to the lead section only. It never names a sibling such as wikimedia_get_zh_article_en or wikimedia_get_zh_search, so the agent must infer the boundary with those tools rather than being told.

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?

Usage is implied by the resource phrasing: reach for this when a brief lead-section summary of a known Chinese Wikipedia article is enough. There is no explicit when-to-use versus when-not guidance, no alternatives named (e.g. the sibling that returns fuller article content or the search tool for finding a title), and no stated prerequisite that the caller must already know the exact title.

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