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

No annotations are provided, so the description carries the full burden, and it does so well: 'keyless' (no auth required), 'Read-only' (safety profile), the data source, and the hostname handling rule (first resolved IP). It omits rate limits and return format, but the operational profile is substantially disclosed.

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?

Four tight clauses, front-loaded with the action and source, then rationale, then edge-case behavior. Every sentence earns its place with no filler.

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 simple one-parameter boolean check with no output schema, the description covers source, safety profile, and hostname handling adequately. A brief note on the return value shape (e.g. exit/non-exit and list freshness) would make it fully complete, but it is close.

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% so the single 'target' parameter is already documented. The description nonetheless adds real meaning beyond the schema: 'For a host name the first resolved IP is used', clarifying resolution behavior the agent couldn't infer from the field alone.

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?

Specific verb+resource: 'Check whether an IP is a current Tor exit node', with the authoritative source named (Tor Project bulk exit list). An agent can immediately distinguish this from generic IP-reputation siblings like ip_reputation or ip_blocklist_check.

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 description implies a usage scenario ('an IP seen in logs may not be the true origin — a useful context signal'), which tells the agent why to reach for it. However, it names no alternatives or exclusions relative to the many IP-checking siblings, leaving the when-to-use decision partly to inference.

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