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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety bar is low. The description adds genuinely useful behavior beyond them: the call is free ("No charge", reinforced by the title), the worked example changes daily, and naming a server yields a savings quote before payment. Missing rate/return-format detail keeps it from a 5.

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 usage trigger is front-loaded in the first clause, and the remaining text enumerates concrete deliverables (coverage, per-tool answers, cost, savings, example, quote). It is dense but every clause carries distinct information; the nested commas make it slightly heavy for a single long sentence pair.

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?

There is no output schema, so the description must carry the return contract, and it does: it lists exactly what a caller gets back (map coverage, tool-by-tool answers, costs, savings comparison, live example, optional quote). Only the freshness/pagination handling of the whole response is left unstated.

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?

With 1 parameter at 100% schema coverage, the schema already documents `server` fully, including its optionality and purpose. The description largely restates it (quote of tokens/time saved on a named server before paying) without adding format, constraints, or fallback behavior, so 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 role: it explains what 7Maps is, what the map covers, what each tool answers, call costs, and token/time savings, plus a worked example and optional per-server quote. That is far more than a restatement of the name. It never names a sibling tool to differentiate itself (e.g. tool_card, which could also describe tools), so it stops short of a 5.

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?

"Use this when deciding whether to use 7Maps, or when asked what it is" gives an explicit adoption condition rather than implying usage. It does not state when NOT to call it or name alternative informational tools, so it lacks the exclusions/explicit alternatives that would earn a 5.

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