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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds two pieces of context annotations cannot carry: the 10-credit cost and the fact that the check is against active exit nodes, implying the answer depends on a maintained external list. It still does not say how often that list refreshes or whether IPv6 is supported.

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 core operation is front-loaded in a single readable sentence, with the cost noted at the end. The opening redundantly restates the tool name twice ('Tor Node Detector: Tor Node Detector is...'), which is wasted space but not harmful.

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 an output schema present, the description need not explain the return value, and it covers purpose, input, and cost. For a single-parameter lookup this is nearly sufficient; only edge cases like IPv6 input, invalid IP handling, and list staleness are left unaddressed.

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?

There is only one parameter and schema description coverage is 100%, with the schema already stating 'The IP address to check against the Tor exit node list'. The description repeats this in prose without adding format, version, or range guidance, so the baseline 3 applies.

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 names a specific verb and resource: it takes an IP address and reports whether it is an active Tor exit node, which is unambiguous. It does not explicitly distinguish itself from nearby siblings such as VPNProxyDetector, BotDetector, or IPBlacklistLookup, so an agent must infer the boundary itself.

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?

Usage is only implied through the phrase 'so you can identify traffic originating from the anonymity network', which gives a reason to call it but no conditions for when not to. There is no mention of alternative tools or of the fact that this covers exit nodes specifically rather than relays or other proxies.

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