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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context: it returns candidate IDs rather than full records, and tells the agent to prompt the user when there are multiple matches. It does not cover pagination or the limit/offset behavior, but it exceeds the annotation baseline.

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 compact sentences, front-loaded with the core search action. The last sentence about not inventing journal/place/file edits is slightly tangential for a search tool but serves as a useful guardrail against hallucinated scope.

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?

Covers purpose, disambiguation, and scope boundaries, which is adequate for a read-only search with annotations. However, with no output schema and only 25% parameter coverage, it should explain return shape or parameter meaning more fully; the description stops at 'return candidate IDs' without saying what an ID is or how to use it.

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 25%; only the 'limit' parameter carries a description. The description does not explain the query, offset, or itemType semantics (e.g., that itemType is fixed to 'list'). Baseline 3 applies because the schema partially documents the key parameter, but the description misses the chance to compensate for the low coverage.

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 (Find) and resource (signed-in user's Tineo Library Lists) scoped by title or description. It also distinguishes from siblings by noting these are 'freestanding Library Lists, separate from trip packing/checklists,' which rules out generate_packing_list and similar tools.

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 a clear use context ('Find the signed-in user's Tineo Library Lists by title or description') and a disambiguation instruction ('when several titles match, ask the user to select one'). It also bounds usage ('Only lists are supported; do not invent journal, place or file edits'). It stops short of naming the natural alternative siblings (library_list_get, library_list_edit).

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