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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the mutation/safety profile is covered. The description adds useful sequencing context (all other work24 tools depend on it), but says nothing about credential prerequisites, session lifetime, or what happens on repeated logins — gaps that matter for an auth tool.

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?

Two short sentences, the imperative ordering instruction front-loaded, and zero filler. Nothing could be removed 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?

For a 5-parameter login tool with no output schema, the description covers the essential 'do this first' contract and the schema covers the inputs. It leaves the post-login state undefined — no indication of what the login yields, how long it lasts, or how failures surface — which is a real gap for an auth entry point.

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 every parameter (business_registration_no, account_link_id, member_type_code, isoa_no, business_management_no) is already documented in the schema. The description adds no parameter meaning of its own, so the baseline of 3 applies.

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?

States a specific verb and resource ('Login to work24 (고용24)') plus the authentication mechanism ('공동인증서 / corporate joint certificate'), so the agent knows exactly what operation this is. It implicitly separates itself from work24__auth__session__status by being the login step, but never names that sibling or any alternative explicitly.

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' gives explicit ordering guidance that an agent can act on. It stops short of exclusions — nothing tells the agent what to do if a session already exists (e.g. check work24__auth__session__status instead of re-logging in).

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