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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), so the description adds context beyond them: spam tokens are excluded from the total, and there is a concrete cost/rate limit (25 free calls/day, then $0.01 USDC via x402). It does not disclose pagination or how 'top tokens' is bounded, 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?

Front-loaded with the trigger condition, then value proposition, then outputs, then inputs and cost in a logical order. Slightly redundant in places ('One call instead of balance + tokens + history' echoed by 'in one answer') and the input list duplicates schema text, but no sentence is wasted overall.

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 carries the full burden and does so: it enumerates the return payload (SOL balance, top tokens with USD values, estimated total worth, recent activity), the exclusion of spam from the total, the network default and its real-money implication, and the cost model. An agent has everything needed to call and interpret it.

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 parameters are already documented in structured form; the description largely restates them. It adds only thin extra context ('Default mainnet-beta (real money)', 'Leave it out for mainnet'), which matches the baseline-3 expectation when the schema carries the parameter detail.

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 ('what a wallet holds or is worth') and immediately scopes it against named siblings: 'One call instead of balance + tokens + history.' An agent can distinguish this aggregate view from the granular sibling tools 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?

Gives an explicit trigger ('Run when asked what a wallet holds or is worth') and names the alternatives it replaces (balance + tokens + history), plus a qualifier that spam is excluded from the total. Nothing about when to prefer it over the granular tools is left to inference.

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