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

Beyond the readOnly/idempotent/destructive annotations, the description discloses that the tool merges real-time availability with the static library/seat-catalog.json, defines the tri-state boolean preference semantics (true=prefer, false=avoid, null/omitted=no preference), states that graduate-only rooms are excluded by default, and requires a LIBRARY-authenticated session. These are meaningful behavioral traits an agent could not infer from annotations or schema alone.

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 information-dense and front-loads the core purpose before any secondary guidance. Every sentence earns its place, though it is a single run-on paragraph that could be bulleted, and the read-only claim and mcp_session_id note partially duplicate what annotations and the schema already state.

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 10-parameter tool with no output schema, the description thoroughly covers input semantics, the graduate-only default, authentication requirements, and the downstream workflow with prepare_reserve_library_seat. The main gap is the return value: the description never indicates what the ranked recommendation list contains or how a chosen seat should be forwarded to the reservation step, which matters more here because no output schema exists.

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 is 3. The description adds value by explaining the null/omitted meaning for all preference booleans (not in the schema), the default-exclusion rule behind include_graduate_only, and the LIBRARY login requirement tied to mcp_session_id. The added meaning is useful but modest because the schema already documents each parameter individually.

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 names a specific verb (순위화합니다 / ranks), a specific resource (currently reservable library seats at SSU Campus), and a specific method (based on user preferences), which sets it apart from sibling tools like get_library_available_seats, get_library_seat_status, and get_library_seat_catalog. It also explicitly names prepare_reserve_library_seat as the downstream step, so the tool's role in the reservation workflow is unambiguous.

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 explicit workflow guidance: prepare_reserve_library_seat should only be called after the user selects a recommended seat, and include_graduate_only=true should only be used for graduate students since graduate-only reading rooms are excluded by default. It does not explicitly contrast with the status/catalog siblings, so an agent must infer when to prefer this ranking tool over get_library_available_seats or get_library_seat_status.

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