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

Annotations only indicate readOnlyHint=false and destructiveHint=false, which does not clarify what 'initialize' actually does. The description reveals that a login is required but does not disclose side effects, whether initialization resets previous state, whether it is idempotent, or whether it returns a job identifier or other status needed for subsequent calls.

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 one efficient sentence that front-loads the critical prerequisite before stating the function. There is no wasted wording, though a slightly structured breakdown of the init workflow could improve scannability.

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?

This tool part of a stateful multi-step workflow, but the description does not explain what output or state the initialization produces, how the agent should proceed afterward, or how this relates to the sibling purchases__page/result/search tools. Without an output schema, the agent is left guessing about the follow-up steps.

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 input schema already documents all parameters with 100% coverage. The description adds value by linking account_link_id to the prior login call ('same account_link_id') and by confirming the date range mapping to date_from/date_to, which goes slightly beyond the schema's standalone parameter descriptions.

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 uses a specific verb ('Initialize') and identifies the resource ('KB Biz Card purchases inquiry') and scope ('for a date range'). It clearly distinguishes from sibling init tools by naming 'purchases' rather than approvals or payments, though it does not elaborate on what initialization entails.

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 explicitly states the required prerequisite: a prior kb_biz_card__session__login call with the same account_link_id. However, it gives no guidance about when to use this tool versus the sibling purchases__page, purchases__result, or purchases__search tools, nor does it clarify the intended call sequence beyond the login requirement.

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