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

Annotations only cover safety flags (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=true); the description goes well beyond them by disclosing that execution is keeper-driven, that orders queue under an agent grant or fall back to an approval flow, and that autonomous stops enforce a signed minimum and may remain unfilled after a price gap. Those are exactly the behavioral traits an agent cannot infer from structured fields.

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?

Roughly five short sentences, front-loaded with the core action and trigger semantics before routing, grant, and gap-fill caveats. No sentence is redundant: each adds routing, execution, or constraint information.

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?

There is no output schema, so the description carries the return-shape burden and does so — it tells the agent the outcome is either a queued order under a grant or an approval link with status needs_approval. Combined with grant prerequisites, keeper execution, and gap risk, nothing material for correct invocation is missing.

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%, so the baseline is 3, and the description earns an increment by fixing the unit convention ('HUMAN units') and restating the triggerPrice quote direction (tokenOut per 1 tokenIn) plus its strict-floor behavior. It does not add detail on slippageBps, requestId, or note beyond what the schema already documents.

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 ('Place a stop-loss') and immediately defines the trigger semantics ('sell amount tokenIn for tokenOut if the price falls to triggerPrice, quoted tokenOut per tokenIn'). It explicitly distinguishes itself from the closest sibling, place_limit_order, so an agent can route without opening either 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?

Gives an explicit when-to-use rule keyed to market direction: use place_limit_order to sell ABOVE the market (take profit), this tool for protection BELOW it. It also states the precondition path (must be covered by an active agent grant) and the fallback (returns an approval link with status needs_approval) when it is not.

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