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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so safety is largely covered. The description adds useful context that syncing is batched and that the scan looks for broken merge tags and TBD placeholders. It still doesn't say whether sync overwrites existing custom values, whether validate/diff touch remote state, or what auth scope is needed.

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 tight sentences with the capability front-loaded and a concrete invocation example. Nothing is redundant, though the example sentence adds less value than a sentence describing the diff mode would.

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 multi-mode tool with a write path and no output schema, the description omits what each mode returns (e.g., a report of broken merge tags, a diff listing) and what sync actually changes. It is enough to start a call but not enough to interpret or safely sequence one.

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 both parameters and the action enum are documented structurally; baseline is 3. The description's example demonstrates a plausible parameter combination but adds no semantics for what 'diff' compares or what locationId defaults to when omitted (no required params).

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 specific verbs and resources: batch-sync Custom Values plus scan SMS/email templates for broken merge tags or TBD placeholders. It clearly reads as a sub-account custom-values tool, distinct from the agency-level siblings like ghl_agency_doctor and ghl_snapshot_diff_audit. However, the 'diff' mode is never explained, so the stated purpose covers only two of the three actions.

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?

There is no guidance on when to pick this tool over alternatives, and no explanation of when to choose validate vs diff vs sync. The example call only demonstrates syntax, not decision criteria. An agent must infer that 'sync' is the mutating path and validate/diff are read paths entirely from the enum values.

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