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

The annotations already indicate the operation is neither read-only nor destructive, and the description adds useful context that the login uses NPKI AnySign and must precede other provider calls. It does not disclose behaviors like session timeout, repeat-login behavior, or failure outcomes, but the core side effect of establishing a login is clear.

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 two short sentences with the ordering instruction front-loaded before the purpose. It contains no filler and does not redundantly repeat parameter details from the schema.

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 login tool with fully documented parameters, the description provides the essential ordering context and the certificate mechanism. It could note whether to check session status afterward or what the response indicates, but the schema and straightforward operation make it sufficiently complete.

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%, so the baseline applies: auth_provider, account_link_id, and business_registration_no are fully documented in the schema. The description's mention of 'NPKI AnySign' aligns with the auth_provider default but adds no new parameter-level meaning.

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 'Login to COMWEL via NPKI AnySign certificate,' naming a specific action, resource, and authentication method. It also scopes the tool to 'this provider,' which clearly distinguishes it from sibling logins like hometax__session__login or work24__auth__npki_session__login.

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?

It explicitly says 'Call this FIRST before any other tool for this provider,' giving strong ordering guidance. However, it does not mention when not to use it or point to the sibling comwel__auth__session__status as a way to verify an existing session, so it lacks full exclusion/alternative guidance.

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