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

Annotations already cover read-only, idempotent and closed-world behavior, so the bar is lower. The description still adds real value beyond them by disclosing that terms are expiring and that free capabilities return an explicit zero quote with no payment handshake required. It stops short of describing what happens when a quote lapses or what errors look like.

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?

Two sentences, both front-loaded and information-dense, with no filler. The payment-avoidance note is placed after the core definition, which is the correct ordering.

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?

With no output schema, the description does the job of naming the returned fields, and it flags the temporal validity of the terms. What is missing is only edge-case behavior: what an expired quote yields, and whether the quote must be re-fetched before invoking.

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 coverage is 0% for the single required parameter, so the description must carry the burden of explaining capability_id. It only implies that one capability is quoted per call ("one intended invocation") and never says where the ID comes from or how to obtain it from find_routes or search_capabilities.

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 gives a specific verb and resource ("Returns exact, expiring terms for one intended invocation") and enumerates the returned fields: amount, currency, expiry and payment offers. That clearly separates it from invoke_capability or get_execution, though it never names a sibling to contrast with explicitly.

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 phrase "for one intended invocation" implies this is a pre-invocation step, and the note that free routes never require a wallet or payment handshake tells the agent when payment setup is unnecessary. However, it never states when to call this versus get_capability or get_route, nor what to do after the quote expires.

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