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

With no annotations provided, the description handles transparency by stating it retrieves information without executing anything. The phrase 'Then use xpay_run to execute' implies this tool is read-only. It doesn't disclose error handling or authentication, but for a details tool, the core behavior is adequately conveyed.

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 three sentences, front-loaded with purpose, then usage guidance, then next step. Every sentence carries meaning with no filler or repetition of schema details.

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 one-parameter tool with no output schema, the description fully explains what the tool returns and its position in the workflow. No additional context is needed for an agent 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?

The schema has one required parameter, slug, with a description that already explains its origin ('Server slug from discover results'). The tool description adds context by mentioning xpay_discover, but this is minimal extra value. Baseline of 3 is appropriate given the schema covers all parameters.

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 tool returns the full tool list, input schemas, and pricing for an XPay server. It explicitly distinguishes itself from siblings by mentioning xpay_discover and xpay_run, making the specific resource and action unambiguous.

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 provides explicit usage context: 'Use after xpay_discover' and 'Then use xpay_run to execute a specific tool.' This clearly sequences the tool relative to its siblings, indicating when to use it and what to do next.

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