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

Beyond the readOnlyHint/idempotentHint annotations, the description adds valuable behavioral details: the exact status enum, the distinction between missing and invalid session IDs, and the fact that sessions persist across server restarts via the database. No contradictions with annotations exist.

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 compact but information-dense: it front-loads the purpose, then systematically explains all status values, practical usage guidance, and persistence behavior. Every sentence contributes meaning without redundancy.

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 compensates by explaining the status field and the linked field for providers. It also covers the key operational context—when to call it, what each status means, and how to recover from an invalid session—making it sufficient for correct invocation.

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 schema already documents mcp_session_id and covers 100% of parameters, so the baseline is 3. The description adds meaning by tying the absence or invalidity of the parameter directly to the NO_SESSION and INVALID_SESSION statuses, which goes beyond the schema text.

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 it returns the current authentication session status for SSU Campus, which is a specific verb and resource. It also distinguishes itself from sibling auth tools like start_auth and logout_all by enumerating the exact status values and their meanings.

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 tells the agent to call this tool before invoking other authentication tools to reduce unnecessary AUTH_REQUIRED retries. It also directs the agent to start_auth when INVALID_SESSION occurs and warns not to treat that state as a login failure.

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