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

With no annotations provided, the description should disclose behavioral traits like output format, error handling, rate limits, or side effects. It only states the basic operation, leaving the agent uninformed about what to expect or whether the tool is safe.

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 description is very concise (one sentence) but lacks structure or additional detail. It is not verbose, but the brevity sacrifices clarity on nuances like return format and usage context.

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?

Given no output schema and no annotations, the description should provide more complete context including expected output (e.g., domain name or record) and possible failure modes. The current description leaves significant gaps for an agent to make informed decisions.

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?

The sole parameter 'ip' is a string with 0% schema description coverage. The description adds no extra meaning (e.g., supported formats, validation rules) beyond the parameter name. The type 'string' alone is insufficient for an agent to construct valid input.

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 'Reverse DNS (PTR) lookup for IP address' clearly states the specific operation (PTR lookup) and the resource (IP address). It is distinct from sibling tools like dns_lookup and whois_lookup, which cover different DNS and IP-related functions.

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 provides no guidance on when to use this tool versus alternatives (e.g., for forward DNS lookups, use dns_lookup). There is no mention of prerequisites, limitations, or recommended contexts.

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