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

With no annotations, the description carries the behavioral burden. It discloses what is measured, that measurements were taken 'this minute from our server,' and even notes the official RPC's throttling quirk. It does not state the output format explicitly, but as a zero-parameter read-only status tool, the disclosed behavior is largely sufficient.

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?

Three short sentences pack the core purpose, data points, measurement window, and a practical use case with no wasted words. The front-loaded question-style opening immediately signals what the tool does.

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 status tool with no output schema, the description is complete: it states what is reported, how current the data is, where it is measured from, and why an agent would call it. Nothing essential is missing for selecting and invoking the tool.

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 the schema coverage is 100%, so there is no hidden input meaning to document. The description still adds value by explaining what the result conveys: latest block, lag, and response time.

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 identifies the resource (Arc RPC endpoints) and the action (report which one is answering and how fast, including latest block, lag, and response time). It distinguishes itself from sibling status tools like arc_agent_status or arc_faucet_status by focusing specifically on RPC performance rather than agents, faucets, or wallets.

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 concrete use case: when Arc's official RPC throttles with a bug-like error, use this tool to pick another endpoint. It provides clear context but does not name explicit alternative tools or state when not to use it, though no sibling appears to cover RPC status.

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