Sign-in link

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

The description adds non-obvious behavioral context beyond the annotations: asking for the link 'starts, replaces and cancels nothing', which pre-empts the natural assumption that generating an auth link invalidates prior tokens or begins a session. That is genuine value on top of readOnlyHint/idempotentHint. It does not address expiry or whether the link is single-use, which is modest additional context this tool could carry — hence a 4 rather than a 5.

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 scoping sentence comes first, then the usage triggers, which is the right order for an agent scanning for fit. Dense but nearly every clause carries information; the 'starts, replaces and cancels nothing' construction is slightly tangled but earns its place.

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?

An output schema exists, so return values need no explanation. With zero parameters, explicit error-state triggers, and instructions on how to hand the result to the user, an agent has everything needed to select and invoke this tool 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?

The tool takes zero parameters, so the schema is complete and no compensation is required. The baseline for a no-parameter tool applies; there is nothing the description could usefully add.

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 names a specific resource — the person's 'My connections' link — and enumerates its scope (connect own HKTVmall account, reconnect, share with household, or stop a shared connection). That is clearly distinct from every sibling (cart, orders, products, reviews, search). It stops just short of a crisp leading verb like 'Get' or 'Return', but the resource and its boundaries are unambiguous.

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 gives explicit trigger conditions: when a tool returns not_signed_in, session_expired, or connection_disconnected, or when the person asks to connect HKTVmall. It also names what to do with the result ('give the person the url and nothing else'), leaving almost nothing to inference.

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