ListHighlights

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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is fully covered by structured data. The description adds only that notes are returned alongside passages; it says nothing about pagination limits or ordering, though the schema carries pagination. Baseline 3 is appropriate.

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?

A single efficient sentence with the resource and scope front-loaded and zero padding. Every clause ('one item', 'with any notes they added') carries information.

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 a full output schema and annotations covering safety and idempotency, the description only needs to convey purpose and scope, which it does adequately. Minor gap: it does not clarify ordering or how this differs from GetItemWithHighlights, which is the one ambiguity an agent would face.

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%: item_id, limit (1-100) and cursor are all documented in the schema, including guidance to find item_id via ListItems or SearchLibrary. The description adds no parameter-level meaning beyond that, 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 and resource ('List the passages the user highlighted') and scopes it to 'one item', with the extra detail that attached notes are included. It separates itself reasonably from the broader ListRecentHighlights, though it does not explicitly name the overlapping GetItemWithHighlights sibling.

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?

No when-to-use or when-not-to-use guidance is given, and no alternative is named despite several siblings (Matter_GetItemWithHighlights, Matter_ListRecentHighlights) that cover similar ground. The 'in one item' phrasing implies a scoping condition but leaves the agent to infer which sibling to pick.

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