port_info

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=true. The description adds value by explaining the return format (same fields as `list_dev_servers`) and handling edge cases (nothing listening or not a recognised dev process). No contradiction with annotations.

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 three sentences, with the key verb 'Read-only' front-loaded. Every sentence adds necessary information: purpose, return format details, and usage scenario. No wasted words.

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 presence of annotations (read-only, idempotent, non-destructive) and an output schema (implied), the description is complete. It covers behavior for all inputs (port in range) and edge cases (free port, unrecognised process). The tool's scope is well-defined.

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% with a well-described parameter (port). The description adds 'TCP port number, 1–65535, e.g. 3000,' which mirrors the schema. Since the schema already does the heavy lifting, the description does not add significant new semantics beyond clarifying the example.

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 clearly states the tool inspects a single TCP port and reports the dev server holding it. It distinguishes from sibling tools like `list_dev_servers` (which lists all servers) and implies a specific function ('what's on :3000?').

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 explicitly says 'Useful for answering "what's on :3000?" before starting or killing something,' which provides clear context for when to use. However, it does not explicitly mention when not to use or list alternatives, though sibling tool names provide some guidance.

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