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

Annotations already declare readOnlyHint=false and destructiveHint=true, so the safety profile is covered. The description adds genuinely useful context beyond that: the concurrency requirement that the SyncToken must be the current one, and that the response carries a new SyncToken. It stops short of stating what a failed/conflicting update does.

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 with zero filler. The core action and the SyncToken prerequisite are front-loaded, and the return value is appended compactly.

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 destructive mutation with no output schema, the description covers the prerequisite token, the return payload, and the new token. Combined with a 100%-covered schema, an agent has enough to call it correctly; only error/conflict behavior is left implicit.

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 100%, so the entity and company parameters are already fully documented, including sparse-update semantics. The description only restates the Id/SyncToken requirement, adding little beyond the schema, 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 (Update) and resource (an existing estimate) scoped to QuickBooks Online, which naturally separates it from create_estimate, delete_estimate, get_estimate and search_estimates. It never names a sibling explicitly, so the distinction rests on the verb alone rather than deliberate routing.

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 gives a prerequisite (requires Id and the current SyncToken 'as the last search or write returned it'), implying a fetch-then-update flow, but does not state when to prefer this over update_estimate's alternatives or what to do when the token is stale. Usage is implied rather than spelled out.

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