vm_backup_policies

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

With no annotations, the description carries the full burden and does so well: it declares read-only access, the Reader role prerequisite, the unknown-type fallback ({"type": <name>, "unparsed": true}, never dropped), the found: false behavior for unknown/ambiguous subscription names, and the skipped/capped coverage semantics. It stops short of describing pagination behavior or result volume.

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?

Purpose and safety profile are front-loaded in the first two lines, and the remaining dense blocks each document a distinct behavior (output shape, fallback, parameter semantics, coverage flags) with no filler or repetition.

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 describe returns, and it does so thoroughly: per-policy fields, the unparsed fallback, and the coverage flags. The only real gap is the unexplained max_pages control, which matters for a paginated multi-subscription read.

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 0%, so the description must compensate. It fully explains subscription (id or display name from list_subscriptions, None = all, ambiguous name yields found: false), but max_pages is never mentioned except obliquely through the 'budget ran out' coverage flag, leaving one of two parameters undocumented.

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 the specific resource (Azure VM backup policies in each Recovery Services vault) and the exact payload (schedule and retention), so an agent knows precisely what it retrieves. It lacks an explicit verb (List/Get) and its differentiation from siblings is only implicit via a reference to vm_backup_status.

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 states the read-only nature and the required Reader role, and clarifies that subscription comes from list_subscriptions with None meaning all visible subscriptions. However, it never explicitly says when to prefer this tool over vm_backup_status or the other backup/log siblings, leaving routing to inference.

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