Add papers to library

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

Annotations already declare readOnlyHint=false, idempotentHint=true, openWorldHint=true, and destructiveHint=false. The description adds genuine value on top by disclosing deduplication behavior ('Papers already in the library are not duplicated'), which is the practical consequence of idempotency, though it says nothing about permissions or partial-failure behavior.

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 sentences, front-loaded with the action and scope, then the required inputs, then the dedupe caveat. No filler; every sentence earns its place.

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 2-parameter, non-destructive mutation with full schema coverage and no output schema, the description covers purpose, inputs, and the dedupe side effect. It stops short of noting auth requirements or what happens with invalid library IDs, which are minor omissions rather than blocking gaps.

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% and the schema already documents both parameters, including that library_id comes from list_libraries. The description merely restates those parameters ('Provide library ID and list of bibcodes') without adding format, limits, or semantics beyond the schema, so the baseline 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 ('Add') and resource ('papers to an existing library in the user's ADS account'), and the word 'existing' implicitly separates it from the sibling create_library. An agent can identify the operation without opening the schema.

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 tells the agent what to provide (library ID and bibcodes) and that the library must already exist, which implies you need list_libraries first. However, it never explicitly states when to use this versus alternatives such as create_library or get_library_papers, so usage is only implied.

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