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

No annotations are provided, so the description carries the full burden. It does disclose two meaningful behaviors: filtering is scoped to the requesting user's own tracked library (an implicit auth/personalization requirement) and the call has a cost ('Free · 1 credit'). It does not state the return shape, what happens when the library is empty, or whether unmatched ids are dropped silently versus reported.

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?

Three short segments with no wasted words: the core operation first, then the trigger condition, then the cost note. The reader gets the essential behavior in the opening clause.

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 one-parameter filter with no output schema and no annotations, the description should still say what comes back — a filtered subset of the input ids, presumably — and it only implies this. The personalization scope and cost are covered, but the return contract and empty-result behavior are left to inference.

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 coverage is 0% for the single required parameter, so the description must compensate, and it partially does: node_ids are graph node identifiers that will be intersected with the user's library. It never says where valid node_ids come from (e.g., library_search_nodes output) or how the array is treated on partial matches, leaving the format and edge-case semantics undocumented.

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 operation (restrict/filter a list of node_ids) against a precisely defined resource (papers in the requesting user's tracked-paper library). The verb-plus-scope formulation makes it clearly distinct from siblings like library_search_nodes or library_node_context, which retrieve rather than filter.

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?

Gives explicit triggering conditions: use when the user asks about 'my papers' or 'my library'. That is concrete usage guidance rather than implied context. It stops short of naming an alternative tool or stating when not to use it (e.g., for global, non-personalized filtering), so it falls one step below the top.

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