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

Annotations already mark it as read-only, so the safety profile is covered. The description adds useful behavior around card_sn being required for 2011-01-01 or later cards, the lawful-processing requirement, allowed file types, and the per-call point cost. Return-value shape is not disclosed, but the read-only annotation lowers that burden.

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 reasonably concise and front-loads the core purpose before adding usage constraints, legal conditions, and cost. The in-language repetition adds length but is excusable for a Korean-domain tool. No filler or unrelated detail is present.

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 two-parameter read-only verification tool, the description covers input format, source, size, legal basis, and cost. The main gap is not describing the result/output shape, but the tool's purpose and schema already convey what an agent needs for straightforward invocation. Sibling differentiation would be the largest remaining omission.

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 has 100% parameter coverage and describes both image_url and card_sn well. The description mainly restates schema information, with only slight added value by explicitly saying card_sn is optional in general while mandatory after 2011-01-01. This is useful but minimal, so a 3 baseline 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 a specific action: verifying the authenticity of a Korean alien registration card from an image or PDF. It names the resource and the modality, so an agent can understand what the tool does. However, it does not explicitly distinguish itself from the many sibling identi_card_image1-4 or identi_card1-5 variants.

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 provides usable context: image/PDF input, optional card_sn with a mandatory condition for post-2011 cards, and the requirement to have a lawful basis. However, it gives no 'when to use this versus another identi_card tool' guidance, so an agent still cannot easily select among siblings.

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