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

Beyond annotations, the description discloses key behavioral traits: 'moves no money by itself' but the order is real, can expire, and locks a fixed rate. It also warns that some orders are routed to a partner aggregator rather than ChangeNOW, which is essential context for the agent to relay. Annotations already indicate readOnly false, so this description complements rather than contradictions.

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?

While the description is longer than average, every sentence adds needed context: purpose, side-effect caveat, prerequisite workflow, alternative tool, and post-call relay requirement. Important warnings are front-loaded before workflow details, and there is no filler or repetition.

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?

Given 11 parameters with complete schema documentation and an output schema, the description covers the remaining decision-relevant context: when to use it, when to use swap_link, what to confirm with the user, and what to relay from the response. Nothing critical 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?

The input schema has 100% parameter description coverage, so the heavy lifting is already done there. The description adds workflow context around parameters (quote first, validate address) but does not introduce new field-level meaning beyond what the schema provides. Baseline 3 is appropriate.

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 states a specific verb and resource: 'Create a real swap order and return the deposit address.' It clearly distinguishes itself from the sibling swap_link by noting this version creates a real order that exists in support, can expire, and locks a fixed rate. An agent can immediately tell this apart from quote_swap and validate_address.

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 gives explicit workflow guidance: quote first, validate the recipient address, confirm both amount and address with the user, and only call this after explicit approval. It also names the alternative tool swap_link with the exact condition to prefer it, and instructs relaying the executor name from the response.

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