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

With no annotations provided, the description must carry the full burden of behavioral disclosure. It only states a vague purpose and does not mention any side effects, permissions, rate limits, or what the output format is. It does not even specify what the tool does beyond 'reference'.

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 short, but it is under-specified rather than concise in a useful way. It does not front-load any actionable information, and the structure is a bare phrase without additional 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 the tool has one parameter, no annotations, but an output schema, the description is extremely incomplete. It does not explain the input, output, or any edge cases, making it inadequate for an agent to call the tool correctly.

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 a single parameter 'q' with 0% description coverage, and the description does not mention the parameter at all. It fails to explain that 'q' likely represents a port number, leaving the parameter's meaning entirely unspecified.

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 says 'Port Reference: Service + exposure notes for a port number' which hints at providing information about a port, but it lacks a clear verb (e.g., 'lookup', 'query') and does not distinguish itself from sibling tools like portlookup, portquick, and portscan. The meaning of 'exposure notes' is ambiguous.

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?

No guidance is given about when to use this tool versus alternatives. It does not mention any context, prerequisites, or alternatives, leaving the agent to infer the appropriate use case from the vague description.

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