list_tunnels

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

With no annotations, the description carries the full burden. It discloses return fields (public URL, protocol, traffic count) and implies read-only behavior through the verb 'list'. However, it does not explicitly state that the operation is non-destructive or safe, nor does it discuss error cases. Still, it provides meaningful disclosure beyond the schema.

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: two sentences that front-load the purpose and return details, followed by usage guidance. Every sentence is necessary and there is no redundant or extraneous information.

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?

For a simple list tool with one optional parameter and no output schema, the description completely covers what the tool does, what it returns, and when to use it. It also references a sibling tool for follow-up, providing sufficient context for an agent to decide.

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 provides 100% coverage for the only parameter (token), including its optionality and fallback to environment variable. The description adds no additional meaning to this parameter beyond what the schema already states.

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 verb 'list' and the resource 'tunnels', specifying it returns public URL, protocol, and traffic count. It differentiates from siblings by explicitly mentioning use cases like finding a tunnel_id for close_tunnel.

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: to check if a tunnel is running, recover a public URL, or find a tunnel_id for close_tunnel. This provides clear context and indirectly excludes use for creation or closing.

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