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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context beyond annotations: the tool depends on an established session and only exposes departments available to that session. This clarifies why login is required without contradicting the annotations.

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 a single focused sentence that front-loads the critical login requirement before stating the tool's purpose. Every word earns its place; there is no redundant or filler content.

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 read-only filtered selection tool, the precondition and parameters are adequately documented. However, there is no output schema and the description does not describe the return shape or how the selected departments should be used downstream, leaving some ambiguity for the agent.

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%, and both parameters are already well described in the input schema. The description reinforces that account_link_id must match the prior login, but it does not add new semantic meaning for either parameter beyond what the schema provides.

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 verb and resource: 'Select KB Biz Card departments available to the current session.' The login prerequisite adds useful scope, and the resource name distinguishes it from sibling tools like cards__select. However, it does not explicitly differentiate from alternatives or state the return format.

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?

The description clearly states the required precondition: a prior kb_biz_card__session__login call with the same account_link_id. This gives the agent clear context for when the tool can be invoked. It does not mention when not to use it or alternative tools, but the context is sufficient for a simple session-scoped read.

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