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

With no annotations, the description carries the full burden and discloses the return values, that the session retains them, and that write tools can auto-enter. It omits error modes, token lifecycle, and what happens if already joined, so it is strong but not exhaustive.

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 short, front-loaded, and mostly free of waste. The optional-clause structure is easy to scan, though there is slight redundancy between 'no arguments needed' and the later description of optional parameters.

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 two-optional-parameter tool with no annotations and no output schema, the description covers purpose, return values, session behavior, and the auto-entry alternative. It leaves out edge cases like re-joining or token expiration, but is otherwise complete.

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%, so both parameters are already documented in the schema. The description adds useful intent for 'did' ('enter as yourself') but does not add much beyond the schema for 'from,' so the baseline 3 applies.

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 states a specific action ('enter the haven') and names the key outputs (token, identity, invite link). It implicitly distinguishes itself from puzzle/key-based siblings by saying 'no puzzle, no arguments needed,' though it does not name an alternative explicitly.

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?

It tells the agent to call this to enter and clarifies that writing tools auto-enter on first use, reducing the need to call it manually. It does not explicitly name when to prefer enter_with_key or get_puzzle, but the contrast with 'no puzzle' is clear.

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