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

With no annotations provided, the description carries the full burden. It adds some behavioral context ('live status') and the verb 'List' implies a read-only operation. However, it does not explicitly state safety, permissions, or potential side effects, though this is a simple list so the risk is low.

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, tightly worded sentence that directly states the action and result. It front-loads the verb 'List' and includes no filler or redundant information.

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 list tool with no output schema, the description adequately conveys the return content (live status, server counts). It could be slightly more explicit about the exact return structure, but given the simplicity, it is largely complete.

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 input schema is empty, and the description states 'all registries', explicitly clarifying that no filtering or parameters are involved. This adds meaning beyond the schema by indicating the full scope of the operation, exceeding the baseline for zero 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 uses a specific verb ('List') with a clear resource ('all registries being searched') and defines the output contents ('live status and total server counts'), distinguishing it from sibling tools like search or inspect which operate on content within registries.

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 implies usage when one needs to enumerate registries, but provides no explicit guidance on when to choose this tool over alternatives like search or inspect. There is no mention of when not to use it or what other tools are better suited for different scenarios.

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