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

Annotations declare readOnlyHint=true and openWorldHint=true, and the description is consistent with them while adding real context: the transaction is unsigned, the caller signs locally, keys/funds are never seen, and no transaction is sent. It also discloses the response payload (base64 transaction, quote, fees in basis points including integrator fee). Missing only failure/error behavior, which is acceptable given no output schema.

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, front-loaded with the core action, followed by the response shape and the custodial guarantee. Only the closing 'Not investment advice' boilerplate is arguably dispensable, but it is brief and legally relevant.

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 burden of describing the return value and does so (base64 transaction, quote, all fees in bps), plus it clarifies the non-custodial boundaries. Only the absence of error/edge-case behavior keeps it from being fully 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%, with each parameter (taker, amount, inputMint, outputMint, slippageBps) already documented in the schema including the slippage fallback behavior. The description adds no parameter-level detail beyond that, so the baseline 3 applies.

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: 'Build an unsigned Solana swap transaction through a DEX aggregator.' The word 'unsigned' plus 'for a wallet you control' implicitly separates it from solana_swap_quote and other siblings, so an agent can route correctly 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?

The description explains the workflow context (you sign locally; the service never sends transactions) which implies when you'd want this over a quote, but it never names solana_swap_quote or any other alternative, nor does it state prerequisites or exclusions explicitly. Usage is inferable rather than stated.

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