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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, non-destructive), and the description adds real substance beyond that: the two-step call sequence (approval of exactly that PT-USDG, then router swap), the USDG recipient (the wallet itself), and that nothing is signed or sent. It stops short of describing the returned call format or failure modes.

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?

One dense but front-loaded sentence carries the whole operation, followed by two short confirmation clauses ('Nothing is signed or sent. Read-only.'). No filler, and the most decision-relevant information (what it builds, where, before maturity) comes first.

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?

All parameters are fully described by the schema, and the description explains the operation's mechanics well for a build-transaction tool. With no output schema, the one remaining gap is that the shape of the returned unsigned calls is never stated, though 'build the unsigned calls' implies it.

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 documented including formats and defaults, so the baseline is 3. The description loosely ties to parameter semantics ('approval of exactly that PT-USDG', 'with a minimum out') but adds no syntax or format detail beyond what the schema already states.

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 the unsigned calls that sell a wallet's PT-USDG for USDG' — plus chain and execution venue (Robinhood Chain, Pendle's router). The qualifier 'at the market before maturity' implicitly separates it from pt_redeem, so an agent can route between the two without opening schemas.

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 usage context ('at the market before maturity') and notes the approval leg is only emitted 'if needed', which tells the agent the tool is self-contained. It never names pt_redeem or pt_quote as alternatives, so the when-not-to-use side is left to inference.

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