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

The annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered by structured data. The description's contribution is limited to noting that per-destination enabled state is returned, which is useful but modest; it says nothing about ordering, volume, or whether disabled/paused syncs are included in the result.

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?

A single front-loaded sentence with no filler, which is appropriately sized for a no-argument list tool. The only weakness is the loose wording 'on' where 'enabled' would be unambiguous, and the phrase 'every destination that receives new records' largely restates the tool title rather than adding detail.

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 zero parameters, no output schema, and annotations covering the safety profile, the description carries nearly everything an agent needs: what is listed and what status information comes back. It stops short of describing result shape or whether the list is scoped to a project, but that gap is small given the tool's simplicity.

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, which is the baseline-4 case, and there is nothing for the description to disambiguate. It correctly avoids inventing filter options that the schema does not support.

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 gives a concrete verb ('Lists') and a concrete resource ('every destination that receives new records'), plus the returned attribute ('whether each is on'). It implicitly separates itself from export/destination siblings by framing the resource as continuous sends, but it never names those alternatives, so the distinction is inferable rather than explicit.

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 read to perform when it needs to see which continuous sends exist and which are active. There is no explicit when-to-use, no exclusion, and no pointer to nearby siblings such as list_destination_exports or list_connection_destinations, which an agent could easily confuse with this tool.

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