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

With no annotations, the description carries full behavioral disclosure. It clearly states the $0.10 per-call cost, the payment requirement (header, bundle_token, or api_key), and that it returns a payment requirement until properly authenticated. It also discloses the signed nature of the quote, which is a key behavioral trait.

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 informative and front-loaded with the price and core purpose, then covers payment options. It's slightly verbose but every sentence adds value; no filler. The length is justified given the need to explain the payment model.

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 no output schema and no annotations, the description covers the essential return content (signed price with signature and timestamp), the payment requirement, and the purpose. It lacks explicit error handling or example usage, but for a 4-parameter tool this is fairly complete.

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 0%, so the description must compensate. It explains the roles of api_key, payment, and bundle_token, and implies ticker as the asset identifier. It adds meaning beyond the bare schema by clarifying authentication and payment mechanics, though it does not specify ticker formats.

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 states the tool returns an 'Oracle-grade signed XLM price quote' with 'verifiable signature and timestamp', specifying the exact verb and resource. It distinguishes itself from sibling tools like get_xlm_quote by emphasizing the attested/signed nature, making its purpose unambiguous.

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?

It provides context (suitable for contracts and settlement) and mentions the free-tier alternative (get_free_api_key) for payment, but does not explicitly contrast with the free get_xlm_quote or state when to prefer this over a non-signed quote. The guidance is implied rather than explicit.

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