agenthop_join

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

Annotations already declare a non-read-only, non-idempotent, open-world call. The description adds context annotations cannot convey: that the call blocks until the counterparty's opening line arrives, and that the channel only opens after a one-line confirmation. This two-phase handshake behavior is genuinely useful and non-obvious.

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?

Front-loads the action ('Join the other side's room...') and packs the workflow into two sentences with no filler. The second sentence is dense and slightly run-on, which keeps it from a 5.

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?

There is no output schema, so the description correctly states what is returned (arrival of the opening line) and what triggers the channel to open. Combined with annotations covering the safety profile and a fully documented schema, an agent has enough to call this 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?

Schema coverage is 100%, so both parameters (code, accept_files) are already documented in the schema, including the file-saving default. The description only restates 'pairing code' in prose and adds nothing about format or the accept_files toggle, 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?

States a specific verb (join) and resource (the other side's room) plus the credential it consumes (pairing code). An agent can distinguish it from siblings like agenthop_accept, agenthop_create, or agenthop_invite without opening any schema.

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?

Gives an explicit conditional protocol: verify the incoming opening line against your context, and if it does not match, ask the user and do not reply. It also names agenthop_say as the tool to confirm with. It lacks a hard statement of when not to use it at all (e.g., when already joined), so it falls just short of a 5.

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