up_tunnel

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

No annotations provided, so description carries full burden. It discloses reuse behavior, return values (local host/port and tunnel_id), tunnel closure mechanisms (down_tunnel, idle timeout, exit), and exact port binding behavior including failure conditions.

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?

Two sentences, front-loaded with core purpose, followed by lifecycle and optional parameter details. Every sentence adds value with no redundancy.

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 no output schema, description explains return values. Covers lifecycle, parameter behaviors, and constraints. With 9 sibling tools, context is adequate and sufficient.

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 descriptions. The description adds meaningful context: 'connection' requires a tunnel configured, 'local_port' default is config or random, and failure conditions if already open on different port or port taken.

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 specifies a clear verb ('Open or reuse') and resource ('tunnel configured for a connection'), and differentiates from sibling tools like 'down_tunnel' and 'tunnel_list' by stating it does not connect to the database and returns a tunnel_id for later use.

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 states when to use (without connecting to the database) and provides conditions for the optional parameter 'local_port' (fails if port taken or already open on different port). It mentions lifecycle: tunnel closed by down_tunnel, idle timeout, or exit, but does not directly compare to siblings like 'tunnel_list' or 'down_tunnel'.

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