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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's job is to add beyond that — and it does, disclosing that no provider refresh occurs and that a last-sync timestamp accompanies the data. That staleness signal is exactly the kind of behavior an agent needs and can't get from the annotations.

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 short sentences, zero waste. The scope (cached, per workspace) is front-loaded and the negative constraint follows immediately.

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 single-parameter read with no output schema, an agent still doesn't learn the shape of the returned chart (account fields, ordering, whether inactive accounts appear) or the unit/format of the last sync time. The description is adequate but leaves return-side ambiguity that the absence of an output schema makes more costly.

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% for the single required 'input.provider' field, so the description must carry the load. It hints at a provider-scoped read ('cached provider chart') and the stale-refresh guidance implies provider systems, but it never names the supported providers or states that the parameter is required; the enum in the schema does most of the work.

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?

A specific verb (read) plus resource (this workspace's cached provider chart of accounts) with the added detail that last sync time is returned. It does not explicitly differentiate from near-neighbors in the toolset such as list_cached_tracking_options or list_integration_status, so it stops short of a 5.

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?

"Never refreshes a provider; refresh stale charts in IPP" gives a clear exclusion and tells the agent where refresh actually happens, which is valuable given no sibling tool performs refresh. It states context but no positive trigger ('call this when you need the GL mapping without a live fetch'), leaving some inference.

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