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

No annotations are provided, so the tool carries full burden. The description mentions 'offline' which indicates no network dependency. It doesn't disclose output details (e.g., if no port found) or edge cases (e.g., invalid input). The behavior is a simple deterministic lookup, so basic transparency is there, but lacks depth.

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 extremely concise, a single phrase that conveys the essential mapping. It is front-loaded with the purpose. No unnecessary words, and it efficiently communicates the tool's core function.

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 an output schema (though its contents are not shown here), but the description doesn't explain what the output will be beyond 'service name'. The tool is simple, but for an agent to call it correctly, it needs to know the parameter format (port number, possibly string or int) and potential errors. The simplicity of one param mitigates incompleteness, but it's not fully specified.

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 schema has one parameter 'q' with 0% schema description coverage, so the description must compensate. The description implies 'q' is the port number (since it maps port to service name), but doesn't specify format (e.g., integer, string, range). It adds minimal meaning beyond the schema, leaving some ambiguity.

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 'Port Lookup: IANA port → service name (offline)' clearly states the function (lookup), the resource (IANA port), and the output (service name). It distinguishes from siblings like portscan and portquick by specifying offline and the mapping to service name, though it doesn't explicitly name those alternatives.

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 the tool is for looking up a port number to get its service name. It does not explicitly state when not to use it or compare to related tools like portscan or portquick. However, the offline nature and singular mapping suggest it's for simple IANA port lookups, providing implicit context.

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