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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is fully covered. The description adds one genuinely new behavioral fact not in the structured data: the $0.001 USDC cost per call, which matters for an agent deciding whether to invoke it. It says nothing about latency cost or rate limits beyond that.

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?

A single front-loaded sentence with no filler: verb, resource set, chain scope, and price. It is efficiently sized, though the price parenthetical reads as appended rather than integrated.

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?

An output schema exists, so return values need not be described, and the one optional parameter is fully documented. For a low-complexity read-only tool, the only real omission is routing guidance against the closely named sibling oracle.

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% for the single optional parameter (includeLatency), and the schema text already explains that it triggers a live RPC round-trip measurement. The description adds no parameter-level meaning beyond that, so the baseline 3 applies.

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?

States a specific verb ('Fetches') plus three concrete resources (block height, gas fees, node metrics) scoped to Arc Mainnet, so the agent knows exactly what data comes back. It does not differentiate itself from the similarly named sibling arc_network_oracle_query, which is the main gap.

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?

There is no when-to-use guidance, no prerequisites, and no mention of when an agent should prefer arc_network_oracle_query or base_analytics instead. The only usage signal is implicit in the resource list.

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