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

Annotations already declare destructive=true, openWorldHint=true and idempotentHint=false, but the description adds real behavior the annotations cannot convey: the server re-verifies the HMAC permit, re-reads pool/balances, re-simulates with sigVerify true including the NFT-mint partial signature, and only then broadcasts. It also discloses the return values (signature and new positionMint), which matters for a non-idempotent, irreversible operation.

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?

Four short sentences, front-loaded with purpose, then input rules, then the conditional edge case, then the return. No filler and nothing repeated from the schema verbatim without adding context.

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?

For a destructive, open-world mutation with a nested summary object and no output schema, the description covers what the tool does internally, exactly what to pass and where it comes from, the wallet-rewrite edge case, and what comes back. An agent has everything needed to invoke 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 coverage is 100%, so the baseline is 3, but the description adds meaning: the summary must be passed unchanged and is bound by the permit, and unsignedTransaction is only needed when the wallet rewrote the message. This conditional dependency is the kind of guidance the schema alone states only tersely.

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 ("Submit a signed open-position transaction") and immediately distinguishes itself from the sibling prepare_open_position by describing the post-preparation lifecycle (verify, re-read, re-simulate, broadcast). An agent can tell this apart from prepare_open_position and quote_open_position 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?

Usage is clear: this is the step after prepare_open_position, and the inputs must come from that call ("complete summary from prepare_open_position, unchanged"). It also gives a concrete conditional for the optional parameter (wallet rewrote the message via Phantom Lighthouse / ComputeBudget). It stops short of explicit exclusions or failure handling, so not a 5.

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