tmall_login

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

With no annotations, the description carries the burden and does disclose a significant side effect: credentials will be saved and reused automatically. However, it leaves gaps around session establishment, success/failure signaling, and whether credentials are truly optional on later calls despite the schema listing them as required.

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 short sentences, front-loaded with the main action, and no filler. Every word contributes either to what the tool does or to how credentials are handled.

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 3-parameter login tool, the description covers the core flow and credential persistence, but it does not describe the expected result/output, how it relates to tmall_check_login, or what happens if login fails. With no output schema, a bit more context would improve completeness.

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 description coverage is 100%, so the baseline is 3 and the description is not required to add much. It reinforces that username and password are needed on first use, but adds no additional meaning beyond what the schema already provides for each parameter.

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 action ('登录' / login) and the target resource ('天猫/淘宝商家后台'), making it distinct from sibling tools like tmall_navigate or tmall_check_login. The verb-resource pairing is specific and 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 contextual usage guidance: first-time use requires username/password, and subsequent calls reuse saved credentials. It does not explicitly mention alternatives such as tmall_check_login or exclusion cases, but the context is clear enough for an agent to decide when to call it.

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