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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the description need not repeat those. It adds useful context: a per-call cost of $0.001 USDC and byte-identical equivalence to a specific REST endpoint, which helps an agent understand side effects and fidelity. No contradiction with 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?

The description is two sentences with no redundancy. The primary purpose is front-loaded, followed by cost and endpoint equivalence. Every sentence earns its place, and there is no fluff.

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?

Given the tool's simplicity (single optional param, output schema present, read-only), the description is nearly complete. It lists the returned metrics, notes the cost, and identifies the equivalent endpoint. Minor gap: it doesn't mention any refresh rate or that it's a point-in-time snapshot, but that is not critical for correct invocation.

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 schema fully describes the single 'chain' parameter (which Blockscout explorer, default 'base'), achieving 100% coverage. The description adds no additional parameter details, so it meets the baseline of 3 for high schema coverage; it neither enriches nor hinders understanding.

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 states what the tool does: it returns a snapshot of chain statistics from an explorer, listing specific metrics (addresses, blocks, transactions, gas price tiers, average block time, market cap, coin price, network utilisation). This is a distinct purpose, well differentiated from siblings like chain_block_stats or market_scout_address_profile, and the 'one explorer's view' phrasing clarifies scope.

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 conveys a clear context for use (overall chain statistics) but does not explicitly state when to use it versus alternatives, nor does it mention when not to use it. It implies a high-level summary, but there are no explicit comparisons or exclusions relative to the many chain_* and market_* sibling tools.

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