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

Annotations already establish readOnly, idempotent, openWorld and non-destructive behavior, so the bar is lower. The description still adds real value beyond them: units are supplied per counter, fees are denominated in LAX, and the average block time is the explorer's own figure rather than a header-derived one — a meaningful provenance caveat.

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 that says what the tool returns and then layers on units and the mining_stats distinction. It is dense but every clause carries information; the parenthetical caveat and unit note are the only parts that could be trimmed.

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 carries the burden of describing return content, and it does so thoroughly by list and currency. It stops short of stating freshness/snapshot semantics or approximate response shape, a minor remaining gap for a zero-parameter stats 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 takes zero parameters, so the baseline is 4. The only schema-adjacent remark, 'Units are given per counter; fees are in LAX', concerns returned values rather than inputs, and no parameter meaning is needed.

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?

It names the exact resource (chain-wide explorer counters) and enumerates the counters returned: blocks, transactions, addresses, accounts, contracts, verified contracts, tokens, LAX transfers, 24h transaction/fee figures, average fee and average block time. It also distinguishes itself from the sibling mining_stats by noting that mining_stats derives block time from headers rather than the explorer's figure.

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 the content (aggregate chain statistics rather than per-entity lookups), and the mining_stats contrast gives a partial alternative-selection signal. However, there is no explicit 'use this when…' or exclusion guidance against siblings like chain_info, supply_info or network_health, which also surface chain-level data.

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