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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description contributes the shape of the response (connected flag, currency, counts by status), which is genuinely useful given no output schema, but adds nothing about failure modes when no ad account is linked.

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?

One sentence, front-loaded with the primary question (is the account connected) and then the supplementary fields. No filler to remove.

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 parameters and no output schema, the description must carry the return-value burden and does enumerate the fields returned. Slightly terse on edge cases (account not connected, zero campaigns) but adequate for a simple status probe.

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?

Zero parameters, so baseline 4 applies; the description correctly implies the tool is parameterless and scoped to the calling partner, which is consistent with the empty schema.

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?

Names the verb/resource precisely: connection state of the partner's Meta ad account plus currency and campaign counts by status. That is a concrete, distinct payload from siblings like get_stats or list_campaigns, though the description never explicitly contrasts itself with them.

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?

Usage is only implied – an agent can infer this is the lightweight connectivity/health check to call before deeper ad queries, but nothing states when to prefer it over list_campaigns or get_insights, nor any prerequisites (e.g. partner must have a linked ad account).

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