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

Annotations already declare readOnlyHint=false, idempotentHint=true and openWorldHint=true, but the description adds context annotations cannot: the connection happens through an external sign-in page requiring Google/Apple/email plus a verified mobile number for new members, so the agent knows a user-facing handoff is involved. It also states the outcome ('returns the account status'), filling the gap left by the absent output 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?

Three sentences, front-loaded with the action and mechanism, then usage, then the parameter rule and return value. The parenthetical about sign-in providers and mobile number is slightly dense but carries real behavioral information, so little is wasted.

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 one-parameter, open-world, non-destructive mutation with no output schema, the description covers the trigger, the external interaction requirement, the account-creation path via join_code, and the return ('account status'). Remaining gaps are minor, such as what happens if the user abandons the sign-in page or what the status values look like.

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 the baseline is 3, but the description earns more by explaining the conditional semantics of join_code: it is only supplied when a new member saved join answers in this conversation, and its presence causes account creation. That is decision-relevant information the schema text does not fully convey.

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 (connect) and resource (the user's Nepternship account to this assistant) plus the mechanism (Nepternship's sign-in page). It implicitly separates itself from sign_up by reserving this tool for members who want to see introductions or sign in, though it never names sign_up or signup_peek as siblings outright.

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 explicit triggering conditions for both personas: an existing member asking to sign in or view introductions, and a new member with saved join answers and no pending request. It also names the source of the one argument ('Pass join_code from sign_up'), which routes the agent to the correct preceding tool.

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