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

Annotations already declare read-only, non-destructive, closed-world. The description adds genuinely non-obvious behavior: failed transactions are included in the count, only completed days are indexed so today is never returned, and the range is capped at 366 days. These are exactly the surprises an agent would otherwise hit.

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?

Three sentences, front-loaded with the resource and metric list, then the 'day' mode, then the range mode and its constraints. Every clause carries information; nothing is restated from the title or schema.

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?

With no output schema, the description takes on the job of describing return values and does list the metric fields and the top-10 breakdown. The only gap is precedence when multiple optional parameters are combined, and there are no required parameters to worry about.

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 0%, so the description carries the full burden and does so: it names each parameter's meaning, the YYYY-MM-DD format, the 366-day cap, and the 30-day default. It stops short of saying what happens when 'day' and 'from'/'to' are supplied together, which is the one ambiguity left.

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 (Wanchain network activity per UTC day) and enumerates the metrics returned (transaction count incl. failed, failed count, distinct senders, contract creations, block range). It's clear what the tool does, but it never contrasts itself with aggregate siblings like get_crosschain_stats or get_chain_status, so sibling differentiation is implicit rather than stated.

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?

Gives explicit invocation modes: pass 'day' for that day plus its top 10 recipients/senders, pass 'from'/'to' for a daily series, omit both for the last 30 days. That's clear operational guidance, but it explains how to call rather than when to prefer this over alternative stats tools.

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