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

Annotations already indicate non-read-only and non-destructive behavior, and the description confirms it creates a session, which matches. It does not disclose side effects like session invalidation or idempotency, but given the annotations, the bar is lowered. The description adds the ordering requirement but little else about behavior beyond what annotations imply.

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 sentence that immediately conveys the primary instruction ('Call this FIRST') and the action. There is zero fluff; every word earns its place, making it highly efficient.

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?

The description is sufficient for an agent to know when to call the tool and what it does. It could mention the return value (e.g., a session token) but since there's no output schema and it's a standard login step, the current information is adequate. The optional parameter is auto-resolved, so no additional context is needed.

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 only parameter, account_link_id, is fully documented in the schema (100% coverage), so the description need not add more. The description does not mention the parameter, but since the schema already explains it clearly, the baseline of 3 is appropriate.

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 ('Create a Shinhan easy-inquiry session') and the resource ('from a registered ID/password account link'). It also distinguishes itself from other tools by explicitly instructing to call it FIRST before any other tool for this provider, making its role unambiguous among siblings.

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 instruction 'Call this FIRST before any other tool for this provider' provides explicit timing for usage. It doesn't mention when NOT to use it or alternative login methods (like NPKI) for this provider, but given the tool name and siblings, it's clear this is the sole login for Shinhan easy-inquiry, so no exclusion is needed.

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