summary

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

With no annotations, the description carries the behavioral burden and does well: it discloses the return content (summary plus optional lead thumbnail) and the exact-title precondition, which is the key failure mode for this tool. It does not mention error behavior when a title doesn't exist, but the essential traits are covered.

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 sentences, each earning its place: capability, usage hint with examples, then sibling routing. The core capability is front-loaded and nothing is padded.

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?

No output schema exists, so the description must convey returns — and it does (summary plus thumbnail when one exists). Combined with explicit sibling routing and full schema coverage, an agent has everything needed to select and invoke it 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 description coverage is 100%, so both `title` and `lang` are already documented, including the enum values and default. The description only reinforces the exact-title semantics already in the schema, so 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?

Specific verb (Get) plus resource (concise summary of a Wikipedia article) with scope stated: by exact title, plus lead thumbnail when present. It clearly distinguishes itself from article_extract and article_sections, so an agent can pick it without opening schemas.

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?

Explicit routing: exact title required, and if the title is unknown the agent is told to use `search` first. It also names the alternatives for adjacent needs (article_extract for full text, article_sections for outline), covering when-not-to-use.

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