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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so safety is covered. The description adds genuinely new behavior: data is 'probed weekly through the customer request path,' which tells the agent the values can be stale and how they were sourced. No contradiction with the read-only annotations.

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?

Two sentences, zero filler. The freshness caveat and both call forms are front-loaded, and no sentence repeats the name or annotations.

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?

Covers the two call shapes, the data source, and refresh cadence. A tool at this complexity needs little more; only a note on how per-chain detail is keyed (chain id vs name) or staleness tolerance would close the remaining gap.

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 coverage is 100% and the single optional param has its own example ('trace_filter', 'eth_getProof'), so the schema does the work. The description adds only that omitting the param yields an overview and supplying it yields per-chain detail, which is marginal but real.

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 resource (JSON-RPC method support matrix) and verb (get), and names the scoping dimension (per-chain). Nothing in the sibling list covers the same ground; get_chain and list_chains enumerate chains, not method support, so the agent can route cleanly.

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?

Explicitly names both invocation modes and what each returns: no args for the overview, {method} for per-chain detail. That is clear context for choosing a call shape, though it doesn't name an alternative tool or state when not to use it.

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