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

Beyond readOnlyHint/openWorldHint, the description discloses billing behavior ('Not charged if any wallet could not be read'), data provenance ('Token names are read from the chain'), ordering semantics, and an explicit prompt-injection warning that returned names/symbols are data, not instructions. That is exactly the kind of operational and safety context annotations cannot express.

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?

Three sentences with no filler, front-loading what the tool returns before the caveats. The opening sentence is dense with stacked clauses (ordering, valuation rule, aggregation) which slightly hurts scannability, but every clause carries real information.

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 annotations and an output schema present, the description supplies the valuation rule, aggregation behavior, ordering, and cost caveat an agent would otherwise have to guess. It stops short of stating rate limits, behavior on malformed/duplicate addresses (schema covers dupes), or what an empty result means, but no critical calling information is missing.

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 all four parameters (chain, wallets, limit, sinceMinutes) are already fully documented with ranges and defaults; baseline is 3. The prose largely restates the schema ('up to 10 Solana wallets', 'newest first') rather than adding new syntax or edge-case meaning, though it implies the limit/window interplay without going beyond the schema's note that the overlap summary covers every swap found.

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 verb and resource ('Recent swaps of up to 10 Solana wallets you name') and pins down scope: newest-first ordering, USD valuation only where one leg is USDC/USDT/SOL, and an additional overlap/aggregate output. No sibling (catalog, chain_pulse, funding_extremes, oi_movers, perp_scan, sample) could be mistaken for it, so an agent can route here 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?

Usage is only implied: an agent infers this is the tool for inspecting recent trading activity of specific wallets. There is no explicit 'use this when…' statement, no exclusion (e.g. single-wallet lookups, non-SOL chains), and no pointer to an alternative when the wallet list is unknown. The 'solana'-only const in the schema carries the one hard constraint that the prose omits.

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