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

Annotations only say readOnlyHint=false and destructiveHint=false, so the description must carry the rest, and it does: no signature/mandate/real funds, hard refusal on missing quote, batch cap of 20, idempotent skip of repeated source_signature, and the auth requirement. These are exactly the traits an agent needs before calling a ledger-mutating tool.

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-loads the single most important qualifier ('PAPER.') and packs auth, refusal, batching, and idempotency into four tight sentences with no filler.

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?

Covers the mutation's safety profile, auth, batch limits, and failure mode despite having no output schema. Minor omissions remain, such as what a successful record returns or how partial batch failures are handled, but nothing that would cause a wrong call.

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 coverage is 75%, and the description still adds value beyond it by naming the `buys: [...]` batch form with its 20-item limit and by explaining the dedup semantics of source_signature. It leaves ledger, reason, and symbol semantics to the schema, which mostly documents them.

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+resource (records a buy in a paper ledger) and immediately scopes it against real trading with 'PAPER' and the title's 'no money moves'. It also clarifies pricing comes from a real Jupiter quote, which an agent could not infer from the name alone.

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 clear preconditions — no mandate, no signature, no funds, requires Bearer JWT — and a refusal rule (no quote = refused, never a made-up price). It does not explicitly name siblings like signet_submit or signet_paper_sell as the alternative, so routing is implied by 'paper' rather than stated.

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