GetItemWithHighlights

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

Annotations already declare readOnly, idempotent, and openWorld, so safety is covered. The description adds genuinely useful behavioral detail beyond that: the result is capped at 100 highlights/notes and is fetched in two requests, which hints at latency and truncation 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?

Two tight sentences with no waste; the core behavior and its limit are front-loaded before the usage example. Every clause 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?

An output schema exists, so return values need not be explained, and the single parameter is fully documented. The description covers what an agent needs for this simple read tool, though it could note what happens when more than 100 highlights exist (truncation vs pagination).

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?

Only one parameter (item_id) and schema description coverage is 100%, so the schema already explains the ID format and how to obtain it via ListItems/SearchLibrary. The description adds nothing further about the parameter, which is the expected baseline at full 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 precise verb and resource ('Get an item together with every highlight and note on it') and scopes it with a cap ('up to 100'). This clearly distinguishes it from siblings like Matter_GetItem (item only) and Matter_ListHighlights (highlights only).

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?

Provides a concrete use case in the form of a user question ('what did I highlight in this article?'), which tells the agent when this tool is appropriate. It does not explicitly name alternatives like GetItem or ListHighlights or state when not to use it, so it falls short of full routing guidance.

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