Read a recent desktop operation result

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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely new behavioral context beyond the annotations: the cache TTL rules (ten minutes, twelve entries, server restart) and the fact that no separate host execution step is involved. It does not describe the shape or failure mode of a cache miss, which keeps it from a 5.

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 tight sentences with the core purpose front-loaded and the cache constraints following. 'No separate host execution step exists' is slightly oblique but still earns its place by clarifying the architecture.

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 read-only retrieval tool with no output schema and full schema coverage, the description supplies the key missing context (cache expiry and the fact that no re-execution occurs). A brief note on what happens when the result is gone would complete 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 coverage is 100%, and the schema already documents both requestId (source of the ID) and root (installation root default). The description adds no parameter-level detail 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 (Retrieve) and resource (a cached completed desktop result and its MCP image blocks), and qualifies it with 'without executing input again,' which differentiates it from the launch/observe/action siblings. It stops short of naming which sibling produced the result, so an agent must infer the pairing.

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?

The cache lifetime ('up to ten minutes, twelve entries, or server restart') implies when this tool is valid to call, i.e. only for recent operations. However, it never explicitly states when to prefer this over desktop_status/desktop_observe or what to do if the result has expired, so usage is only implied.

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