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

Adds real context beyond readOnlyHint/openWorldHint: the call is free, the returned price is authoritative, and the caller must retain quote_token plus total for a later call. 'Never compute prices yourself' is a useful guardrail. It stops short of saying what happens if the token expires or whether the quote is time-limited.

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?

Three short sentences, no filler, with the cost/authority guarantee front-loaded and the retention requirement immediately after. Nothing is redundant with the name or title.

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 usefully names the return fields (quote_token, total). But for a 4-parameter tool with zero schema coverage it leaves series and country undefined and does not clarify the handoff to the confirming 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 description coverage is 0% across 4 parameters, so the description carries the burden. It clarifies identifier and product_ids only; the 'series' enum (phone/email) and the 'country' ISO-3166 pattern go entirely unexplained in both schema and description.

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?

States a specific verb and resource: a quote for one identifier against product_ids. The phrase 'for the confirmed call' hints that this is a preview step distinct from the commit path, but it never names the sibling check_realtime, so the boundary is inferred rather than stated.

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?

'Show its total to the user and preserve quote_token plus total for the confirmed call' implies a quote-then-confirm workflow, but no explicit when-to-use, when-not, or which sibling performs the confirmed call. The agent must guess that check_realtime is the follow-up.

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