check_chain

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

With no annotations, the description carries the full burden and does reasonably well: it discloses the data source (public RPC, live), that no API key or aggregator is involved, and a concrete cost ($0.005 per check). It does not mention rate limits, latency, failure modes, or the units/precision of gas_price, so it is good but not exhaustive.

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 tight sentences, front-loaded with the action and scope, then the operational facts (open RPC, no key, price). Every clause earns its place; nothing is padding.

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?

There is no output schema, so the description correctly takes on describing return content for latest_block and naming the gas price metric, plus cost and auth profile. It stops short of specifying units for gas_price, block-height semantics, or error/timeout behavior, which leaves minor gaps for a read 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?

Schema coverage is 100% and both params are enums, so the baseline is 3. The description goes beyond the schema by spelling out what each metric yields — 'current gas price' for gas_price and 'number, timestamp, hash' for latest_block — which the enum descriptions ('Which on-chain data point to fetch') do not convey.

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 (check/read) and resource (live on-chain data) and enumerates the exact metrics (gas_price, latest_block) and chains (Base, Ethereum) it covers. An agent can distinguish it at a glance from siblings like verify_fact, check_market, and search_web, since 'on-chain via RPC' is a distinct domain.

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?

Usage is implied by 'live on-chain data' and 'Read live via a public RPC endpoint', which tells the agent the tool is for direct chain reads rather than web or market lookups. However there is no explicit when-to-use/when-not statement and no routing to or away from the sibling tools, leaving the boundary with check_market to inference.

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