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

With no annotations, the description carries the full burden of disclosing behavior. It does reveal the cost (0.05 USDC) and the blockchain (Base), but it does not explain prerequisites, authorization requirements, or what 'read-only' means in this purchase context. The behavioral disclosure is partial but not absent.

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 a single, front-loaded sentence that wastes no words. It efficiently communicates the core purpose and key specifics without unnecessary elaboration.

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?

Even though the tool is simple (one parameter, no output schema), the description is incomplete for an agent: it does not explain what the resulting 'brief' contains, what the tool returns after purchase, or when it should be used. The lack of an output schema heightens the need for return-value context, which is absent.

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% (slug has a clear description), so the baseline is 3. The tool description adds no additional meaning about the slug parameter beyond what the schema already provides.

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 clearly states the action (purchases) and the resource (market brief), with specific details (0.05 USDC, on Base). It distinguishes this paid purchase tool from the sibling read-oriented tools by indicating a transaction rather than a read operation.

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?

No guidance is provided on when to use this tool versus alternatives like get_market_delta or get_market_pricing. There are no exclusions or explicit context for choosing this tool, leaving the usage decision entirely to the agent.

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