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

Beyond the annotations, the description discloses real behavior: no credentials are accepted as MCP input, each call consumes one token, the call spins up an XBOSS task and stores the result, and it is explicitly not a pure read-only operation. That last point is consistent with readOnlyHint=false rather than contradicting it. It loses a point for the confusing fragment about "anonymous taste calls" and for not saying what a successful session leaves behind for downstream 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 most important instruction is front-loaded, which is good, but the body mixes Korean and English, repeats the idempotency rule in several restatements, and includes an opaque phrase ("anonymous taste calls") that reads like transplanted boilerplate. Several sentences could be merged without losing information.

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?

With no output schema, the description carries the burden of explaining what the agent gets back, and it only vaguely says an XBOSS task is created and results are stored; it never states whether downstream tools then work implicitly or whether some session handle is returned. Token cost and credential handling are covered, so it is adequate but not complete for a prerequisite login tool.

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 both parameters are already documented, and account_link_id is fully explained in the schema. The description nonetheless adds genuine meaning for request_idempotency_key, whose schema entry merely defers to "see the tool description": it specifies generate-and-save ordering, reuse-only-for-recovery semantics, and that a provider-specific idempotency_key is a distinct field.

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 Korean sentence "KB국민은행 빠른조회 세션을 기존 연동으로 만듭니다" states a concrete verb (create session) and resource (KB quick-inquiry session over an existing linkage), which separates it from the account/transaction-history siblings. The strong opening directive "Call this FIRST before any other tool for this provider" further pins its role as the entry point. It stops short of a 5 because the purpose statement is buried among idempotency boilerplate rather than stated cleanly up front.

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?

"Call this FIRST before any other tool for this provider" is an explicit ordering rule that tells the agent when to use it relative to the rest of the provider's tools. The idempotency-key paragraph also gives conditional guidance (generate before first request, reuse only to recover a lost response). What is missing is any when-not or cross-provider routing note, though "for this provider" does scope it implicitly.

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