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

The description adds substantial behavioral context beyond the annotations: pricing ($0.01/call via x402 USDC or card key), free tier (first 25 free, failed calls free), and cost implications of repeated calls. It also reiterates the read-only, non-destructive nature, aligning with the annotations while adding useful billing semantics.

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 description is front-loaded with the core purpose and return fields, followed by usage, example, pricing, and safety notes. It is compact and every sentence contributes, though the pricing and safety sentences could be slightly tightened.

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?

Given a simple two-parameter tool with no output schema, the description covers what the tool returns, how to use it, cost structure, and safety profile. An agent has everything needed to call it correctly and understand the billing implications.

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 (lang and title) are already documented in the schema. The description adds only an example (title=Stockholm) and mentions 'any language edition,' which is marginal beyond the schema.

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 and resource: get a short summary of a Wikipedia article. It also lists the return fields (title, extract, description, thumbnail, URL), making the purpose concrete. However, it does not explicitly differentiate this tool from similar siblings like search, extract, or summarize.

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 gives a clear use case: 'Use to ground an agent's answer in a quick, citable fact sheet,' plus an example (title=Stockholm). It does not, however, specify when not to use this tool or name alternatives such as search or extract.

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