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

The readOnlyHint annotation already declares this a safe read, and the description does not contradict it. The description adds that the tool returns the 'full content' of the item, which is behavioral context beyond the annotation (it clarifies that search returns something less than full). It does not mention auth or rate limits, but the annotation covers the safety profile, so this is adequate.

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?

The entire description is a single front-loaded sentence with no redundant words. It states the action and the key contextual clue ('as returned by search') immediately, so every word 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?

For a one-parameter fetch tool with a readOnlyHint annotation and an output schema present (per context signals), the description covers the essential usage: what it retrieves, by which identifier, and where that identifier comes from. There is no missing information an agent needs to make the call correctly.

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?

The schema already documents the id parameter with 100% coverage, describing it as 'Item id from a search result.' The description's 'by id, as returned by search' restates the same information without adding new detail about format or constraints, so it barely adds value beyond the schema. The baseline of 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?

The description names a specific verb ('Retrieve'), a specific resource ('CortexPlus memory item'), and the scope ('full content ... by id'). It also distinguishes from the sibling search tool by noting the id comes from search, so an agent can tell fetch from search at a glance.

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 tells the agent that the id is 'as returned by search', which implies the correct sequence of using search first to obtain an id and then fetch to get full content. It does not explicitly name alternative tools or state when not to use them, so some ambiguity remains with recall/remember, but the search linkage is a clear usage signal.

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