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

With no annotations, the description must carry the behavioral burden, and it does disclose two important traits: read-only and no authentication required. It omits other relevant behavior for a quote-style tool, such as whether the quoted price is locked or expires, so the disclosure is only partial.

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 short sentences, zero filler, with the core purpose front-loaded before the caller constraints. Nothing in it is wasted or repeated from the schema.

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 one-parameter, read-only tool with no output schema, the description adequately conveys both the return content (price and contents) and the currency (USDT). Minor gap: it does not mention quote validity or expiry, which matters for a pricing tool.

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 100% and the schema already gives an example ('voice.pro') for plan_code, so the description adds little parameter-level detail. Describing the return as 'price and contents ... in USDT' implies what the plan_code resolves to, but nothing beyond the baseline.

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 resource ('one star365 plan') and what is returned about it ('price and contents'), which maps cleanly onto the quote semantics of the tool name. It does not explicitly distinguish itself from purchase_intent or purchase_status, so the agent must infer the division of labor from the names alone.

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?

'Read-only, no account needed' tells the agent it can call this freely without auth, which is useful invocation guidance. However, it never states when to use this versus purchase_intent (e.g. call quote before creating an intent), leaving the sequencing to inference.

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