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

Annotations already declare readOnlyHint=true, so the bar is lower; the description goes well beyond that. It explicitly explains the behavior of the stalled state (auto-close after ten minutes, new sync blocked until then), the terminal status set, and how error details are structured across providers (Google/Microsoft). This adds substantial context that the readOnlyHint annotation alone does not convey, and nothing contradicts the annotation.

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?

The description is dense but every sentence earns its place: purpose first, then status semantics, then error detail format, then scoping behavior. Each clause adds distinct value without redundancy. The length is justified by the complexity of the status field and the scoping caveat.

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?

With no output schema, the description carries the full burden of explaining the return values. It covers the main fields (status per campaign, totals, error details), enumerates all effectiveStatus values with their meanings, and explains the stalled/terminal behavior. It also addresses the active Space scoping and how to override it. An agent can invoke this tool and interpret its result correctly based solely on this description.

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 sync_id and space_id are already documented with clear meanings (including the default behavior for space_id). The description adds only a brief pointer to set_active_space, which mirrors the schema's explanation. No new syntax, format, or conditional rules are added that are not already in the schema, so the baseline 3 is appropriate.

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?

The opening sentence states a specific verb-resource pair ('Return a sync's status') and immediately enumerates what is included: per-campaign progress, totals, and structured errors. This clearly distinguishes it from siblings like list_syncs (which lists syncs) and get_brake_status (which checks a different operational condition). The description names the exact status field and values, leaving no ambiguity about what the tool observes.

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 description gives concrete operational guidance: which effectiveStatus values should prompt continued polling versus which are terminal, and explains the stalled state's automatic closure and blocking behavior. It also tells the user how to switch Spaces (set_active_space) and how to override per-call with space_id. It does not explicitly name alternative tools for cancellation or listing, but the polling and terminal-state guidance is directly actionable.

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