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

readOnlyHint=true already covers the safety profile, so the description's added value is real: it discloses that the envelope carries 'no entries' (a non-obvious trait) and explains that 'complete=false means the export is a prefix of the chain's list,' which no annotation conveys. It stops short of noting anything about ordering or how the wallet tool consumes the reference beyond 'unchanged,' 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?

Two tightly packed sentences, front-loaded with the return artifact and then the wallet handoff. The phrase 'and its count, with no entries' is momentarily confusing on first read — the count-with-no-entries juxtaposition could be stated more cleanly — but there is no fillers or 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 an output schema present and readOnlyHint supplied, the description only needs to cover the handoff and the completeness flag, both of which it does. The reference to 'the wallet tool's reference argument' points at a tool not among the listed siblings, a minor dangling reference the agent must resolve elsewhere.

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 both chain_id and max_tokens already carry their own guidance (including the ~5,600 Ethereum token note and the whole-refusal behavior). The description adds no syntax or format detail beyond what the schema provides, so the baseline 3 holds.

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 the exact artifact produced — a 'token_list_reference envelope (chain ID, address, symbol, name, decimals) and its count, with no entries' — rather than a generic 'export'. It also draws a sharp line against the nearest sibling with 'Use list_tokens to read entries yourself,' so an agent can pick between them without opening either 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 states the intended consumer and handoff explicitly: return the envelope 'so a wallet can import token names' and 'pass it unchanged as the wallet tool's reference argument.' It names the alternative (list_tokens) and the condition that selects it, leaving nothing to inference.

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