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

With no annotations supplied, the description carries the full burden and does it well: it names the data sources (public RPC, DexScreener prices), discloses that USD values are estimates and may be null for illiquid tokens, and explains partial-failure semantics — per-chain errors are reported per chain rather than failing the whole call. It does not mention rate limits, address validation, or latency, which keeps it from a 5.

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?

Four dense sentences, front-loaded with the core verb and scope, then data sources, then default behavior, then caveats. Nearly every clause earns its place; the paragraph is a long run-on but contains no filler or repetition.

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?

For a two-parameter read tool with no output schema, the description covers what is returned (native plus curated token balances with USD estimates), where the data comes from, and how partial failures surface. The remaining gap is address input format and any limits on how many tokens are returned, which an agent could still get wrong.

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 must compensate. It does explain 'chains' (optional subset, defaults to all three) but says nothing about the required 'address' parameter — expected format, checksum casing, or whether ENS names are accepted — leaving the most important input under-specified.

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 and resource ('wallet portfolio lookup') plus exact scope: native coin and curated token balances with USD valuation for one address across Base, Ethereum and BSC. The multi-chain framing implicitly separates it from the sibling 'wallet-lookup', but it never names that sibling or states the contrast explicitly, so it stops short of a 5.

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 only implied: an agent can infer this is the tool for a read-only portfolio snapshot, and the 'chains' default is explained. There is no explicit when-to-use versus alternatives (e.g. 'wallet-lookup' for a single chain) and no exclusions, such as not for transaction history or safety checks (that's 'token-safety').

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