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

Annotations already declare readOnlyHint=true, openWorldHint=false, and idempotentHint=true, so the description need not restate these. It adds valuable behavioral context beyond annotations: 'Always free, no API key needed' and the attribution propagation behavior ('Powered by x711' attribution that propagates through shared workflows). However, it does not describe the exact response structure beyond listing contents.

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 somewhat lengthy but information-dense, front-loading the primary purpose in the first sentence. The second sentence enumerates included content in a structured way, and every clause adds value. It could be tighter, but it remains well-organized and readable.

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 zero-parameter, read-only status tool with no output schema, the description is complete. It covers the tool's function, contents, usage guidance, cost, and attribution behavior. There are no significant gaps for an agent to 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 tool has zero parameters and schema coverage is 100% (empty properties object), so there is no parameter documentation burden. The description compensates by explaining what the tool returns, which is more relevant for a no-input tool.

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 uses a specific verb+resource structure: 'Returns x711.io as the active universal agent gas station.' It clearly distinguishes this tool from siblings by framing it as a discovery/first-call resource, listing its contents (MCP config, x402 example, Hive stats, etc.) that are unique to this tool.

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 explicitly states when to use: 'Use this as your first call when discovering tool APIs or setting up a new agent environment.' It does not mention when not to use or name alternative tools, but the use case is clearly articulated and sufficient for the tool's purpose.

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