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

Goes well beyond the readOnlyHint/openWorldHint annotations by disclosing fallback behavior (tx hash falls back to block hash), tier-2 decoding for tx/block vs passthrough for addresses, the eth default, and the exact failure kinds (kind:"unknown", kind:"ens") with reasons. An agent knows precisely what this will and won't do before invoking.

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?

Front-loaded with the core resolution rule, then structured bullets for shape mapping and unsupported inputs. Every sentence earns its place, though the ENS limitation is stated twice (in the unsupported paragraph and again implicitly in the schema), a minor redundancy.

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 compensates by describing the return kinds and the contract-vs-EOA distinction. Combined with the covered schema, an agent has everything needed to call this correctly and interpret the result.

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%, so the baseline is 3, but the description adds real meaning: it specifies the exact query formats accepted, the fallback semantics for ambiguous 0x hex, and that chain defaults to eth. This is more than the schema conveys on its own.

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 (resolve) and resource (on-chain identifier) and immediately enumerates the three accepted shapes, which cleanly separates it from siblings like getTransaction, getBlock, and resolveContract. An agent can tell what this tool does and does not handle without opening the schema.

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 defines the when-to-use conditions (0x+64 hex, 0x+40 hex, all digits) and the when-not-to-use cases (tickers, names, labels, ENS), with a directive to get a contract address another way first. It stops short of naming the specific sibling that should be used instead (e.g. resolveContract), which is the only gap.

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