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

Annotations declare readOnly/idempotent/non-destructive, and the description adds the crucial non-obvious behavior: it returns after durable queue admission and never waits for a provider read. That tells the agent the returned state is not the final data, which annotations alone could not convey.

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 sentences, no redundancy: the first establishes the action and its async nature, the second gives the follow-up. Key constraint (does not wait) is front-loaded rather than buried.

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 two-parameter enqueue tool with no output schema, the description covers the asynchronous contract and where results appear, which is the main risk of misuse. The only real gap is parameter meaning, which the schema also leaves empty.

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 0% and the description never mentions accountId or threadId, so neither parameter's meaning, format, or sourcing is explained anywhere. With two required undocumented parameters, the description should compensate and does not.

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 ('Queue an asynchronous refresh of one cached thread') and implicitly separates itself from the polling sibling get_cached_thread and the RFC lookup variant by emphasizing 'cached thread' and 'refresh'.

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 second sentence tells the agent exactly what to do next (poll `get_cached_thread` for messages and completeness state), which is effective use guidance. It stops short of stating when NOT to use it versus request_cached_rfc_thread_lookup or get_cached_thread directly.

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