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

Annotations already cover destructiveHint=true and readOnlyHint=false. The description adds valuable context: the autonomous pipeline (oracle gate → compliance screen → settlement flow), the default sandbox mode, and that a receipt is returned. It does not contradict annotations, and the sandbox default is an important safety-related behavioral detail.

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?

The description is compact and front-loaded with the primary action. The examples are helpful but three examples may be slightly repetitive; however, each sentence adds useful context (parsing, pipeline, sandbox default). No fluff, but could be slightly tighter.

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 payment execution tool, the description covers the key aspects: what it does, when to use it, how it executes (autonomous pipeline), safety default (sandbox), and output (receipt). Since an output schema exists, the return format is already documented. It does not mention failure modes or authorization requirements, but annotations and schema fill some gaps.

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. The description reinforces the 'instruction' parameter as plain-English and gives examples, but does not add new semantic information about parameters beyond what the schema already provides. The sandbox default is mentioned both in the description and schema.

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 clearly identifies the tool's action: 'Execute a payment from a plain-English instruction.' It names the resource (payment/settlement) and the key differentiator (natural-language instruction vs. structured parameters). The title 'Natural Language Settlement' reinforces this, making it easy to distinguish from sibling tools like settlement.execute.

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?

The description explicitly states when to use it: 'Use this when the agent has a natural-language payment task rather than structured parameters.' It provides concrete examples of appropriate inputs. It doesn't name alternative tools explicitly, but the 'rather than structured parameters' exclusion gives enough guidance for selection among siblings.

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