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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so safety is covered. The description adds value beyond them by enumerating returned fields (id, name, fileName, mimeType, size, linkedMode, externalProvider, externalUrl, uploader, timestamps) and stating sort order ("Newest first") — meaningful since no output schema exists.

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 purpose, then return shape, then ordering, then prerequisite — every clause carries information with no repetition of the tool name or filler.

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 responsibly documents the fields returned and the sort order, and the limit/cursor semantics live in the schema. It is nearly complete; only explicit pagination behavior (what nextCursor means for continuation) is left entirely to the schema.

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 100%, so the baseline is 3. The description goes slightly beyond by explaining where libraryId comes from (list_libraries) and implying cursor-based paging through the ordered listing, adding provenance that the schema's one-line "DocumentLibrary id" does not provide.

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+resource ("List documents (files + external links) in a workspace library") and clarifies scope by noting it covers both uploaded files and links. It distinguishes itself from list_libraries via the discovery pointer, though it does not contrast with search_docs or list_document_versions, which could be confused with it.

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?

"Use list_libraries first to discover the libraryId" gives a concrete prerequisite and ordering of operations, which is exactly the context an agent needs. It does not state when to prefer search_docs over this tool, so exclusions are absent.

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