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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so safety is covered. Beyond that the description adds almost nothing: it does not say whether results are paginated, whether they reflect current sharing state or all possible candidates, or how results relate to report_set_sharing. The implicit hint that these are share-eligible principals is the only added context.

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 wasted words. It is efficient, but its brevity is close to under-specification given the ambiguity with sibling sharing tools.

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?

There is no output schema, so the description must convey what comes back, and it does not: an agent cannot tell whether the result is a list of emails, user objects, group IDs, or paging tokens. For a discovery tool whose output feeds report_set_sharing, that missing return-value context is a real gap despite the simple one-parameter signature.

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 coverage is 100% and the single parameter carries a description ('Dashboard ID'), so the schema does the work. The description never mentions the dashboard at all, so it adds no meaning beyond the schema; baseline 3 applies.

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 verb 'List' and the resource 'members and groups you can share with' are stated, which is clearer than the jargon title 'sharing principals'. However, it omits that listing is scoped to a specific dashboard (the required dashboardId), and it does not distinguish this from the sibling report_get_sharing, which sounds like it returns overlapping information.

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 call this versus report_get_sharing or report_set_sharing, which is the key decision an agent faces in this cluster. The phrase 'you can share with' hints these are share targets, but no explicit workflow (e.g., call this, then pass results to report_set_sharing) is given.

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