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

Annotations already flag idempotentHint=true and destructiveHint=false, and the description reinforces this by stating the transaction is unsigned and never signed or broadcast, which tells the agent the call has no on-chain side effects. The added session-requirement prerequisite is genuine context the annotations do not carry, though nothing is said about expiry or reuse of the prepared transaction.

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 short, front-loaded sentences with zero padding: the output, the precondition, and the safety guarantee. Every clause earns its place.

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 and no parameter documentation, the description covers the essential safety posture but omits the return payload shape and how the required request_id is obtained. It is adequate to know what the call does, not enough to know how to call it correctly.

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% and the single required parameter 'request_id' is left wholly unexplained in both schema and description. The description says nothing about what a request_id is, where it comes from, or whether it ties back to create_solana_payment_request, so the agent cannot know how to populate it.

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 gives a specific verb ('Return') and resource ('unsigned exact SPL-token transaction'), and the words 'unsigned', 'exact', and 'SPL-token' carve out a distinct niche from siblings like prepare_payment and create_solana_payment_request. It stops short of naming those siblings, so an agent must still infer whether it wants this tool or the request-creation ones.

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?

'Solana wallet session required' is a real prerequisite and 'Never signs or broadcasts' implies the intended workflow (prepare, then sign elsewhere). However, there is no explicit when-to-use versus when-not, and no routing guidance against the many neighboring prepare_/create_ payment tools.

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