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

Annotations already declare readOnly/idempotent/non-destructive, but the description adds behavioral facts they don't cover: a hard cap of at most 100 tokens returned and, importantly, a security warning that names, symbols, tags and method names come from untrusted deployers/verifiers. These are the kind of traits an agent must know before trusting or re-using the output.

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 return contract, then the two caveats (native coin, untrusted strings); every clause carries information. It is dense — the first sentence packs the full item shape — but nothing is redundant.

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?

No output schema exists, yet the description enumerates the returned fields, so an agent knows what to expect. The only gap is that the 100-token cap is stated without saying how (or whether) to retrieve more, but for a simple read tool this is largely complete.

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 100%, so the single 'address' parameter (0x-prefixed 20-byte) is already fully documented by the schema. The description adds no additional syntax or format detail beyond that, so the baseline 3 is appropriate.

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 names a specific resource (ERC-20/721/1155 balances of an address) and details the exact shape of each returned row, which cleanly separates it from siblings like explorer_token_holders and explorer_token_transfers. It also explicitly disambiguates native-coin lookups by stating 'LAX itself is not a token: use explorer_address or get_balance.' An agent can route without opening any 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?

It gives an explicit when-not with named alternatives for the native-coin case (explorer_address, get_balance), which is genuine routing guidance. It stops short of telling the agent when to prefer this tool over the other token-related siblings (explorer_token, explorer_token_holders), leaving that to be inferred from the 'balances of an address' framing.

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