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

Annotations already declare readOnlyHint, idempotentHint and non-destructive behavior, so safety is covered. The description adds genuinely useful context beyond them: it discloses what the call surfaces (connection state, freshness, sync progress) and, importantly, the semantic rule that zeros on an unconnected or mid-import store are missing data rather than real figures.

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 purpose is front-loaded in the first sentence and the routing/interpretation guidance follows. The second sentence is long and clause-heavy, but every clause (two triggers plus the missing-data rationale) carries actionable meaning, so little is wasted.

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 burden of explaining what comes back, and it does: per-source status, freshness, last successful sync, and import progress. Combined with the usage triggers, an agent has everything needed to call it and interpret the result correctly.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline is 4. No parameter guidance is needed or expected.

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 description names a specific resource and scope: 'Which data sources are connected for this brand and whether their data is complete,' and enumerates the per-source fields (status, freshness, last successful sync, import progress). This clearly distinguishes it from the sibling data tools like get_sales or get_summary, which return figures rather than connection health.

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 two explicit trigger conditions: 'Call this before reporting figures to someone new to Nuira' and 'whenever other tools return zeros or empty lists.' It also explains the reasoning behind the second trigger, so the agent knows not just when to call but why the result changes interpretation.

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