Zotero List Libraries

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

With no annotations, the description carries the full burden and delivers: read-only/no side effects, local-mode behavior (reads local SQLite, fast, includes RSS feeds) vs web-mode behavior (queries /groups, no feeds), and the important caveat that the active library is NOT flagged in output. This is unusually rich behavioral disclosure for a list tool.

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?

Content is front-loaded with the what and the workflow routing first, and most sentences earn their place by covering mode differences and the active-library caveat. It is dense and slightly long, with a trailing example that is near-vestigial, keeping it out of the top tier.

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?

An output schema exists, so return values need no explanation, yet the description still tells the agent what each entry contains (library/group ID, display name, item count) and warns about what it does not contain (the active library flag). Nothing needed to call this tool correctly is missing.

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?

Zero parameters, so schema already provides everything and the baseline is 4. The description correctly notes 'No parameters' and clarifies that the library_type='user' switch belongs to zotero_switch_library, preventing misuse, but there is no real parameter meaning to add.

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 states a precise verb+resource ('List every Zotero library this MCP can address') and enumerates the three sub-types returned (personal, group, RSS feed libraries). It explicitly distinguishes itself from the sibling zotero_get_collections, so an agent can tell them apart without opening either 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?

It states the exact context for use ('discover a library ID before calling zotero_switch_library' as a read-then-switch workflow) and an explicit exclusion routing to zotero_get_collections for viewing collections in the current library. Both when-to-use and the alternative are named.

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