stale_accounts

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the bar is lower. The description adds real behavioral context beyond the structured fields: the two required Graph permissions and the inclusive handling of never-signed-in accounts, which directly affects result interpretation.

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?

Two sentences, no filler, and the substantive scope definition is front-loaded before the permission note. Every clause earns its place.

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?

For a one-parameter read-only report with an output schema present, the definition supplies scope, edge-case semantics, and auth requirements. The only meaningful gap is the absence of routing guidance relative to the sibling tools.

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% for the single 'days' parameter, so the description must carry the burden. 'Last N days' and 'never-signed-in included' clarify what the window means and that null sign-ins are not excluded, which is genuinely useful. It still does not state the unit bounds, the default of 90, or whether the window is measured to now, so it only partially compensates.

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?

States a precise scope: enabled accounts with no successful sign-in in the last N days, explicitly including never-signed-in accounts. That is a specific resource and filter definition an agent can distinguish from a generic account list. It does not, however, differentiate itself from the sibling reports (secure_score, mfa_coverage, privileged_roles), so it stops short of a 5.

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?

The description explains what the output set contains but never says when to reach for this tool versus the sibling reports, nor any exclusion or prerequisite beyond the permission list. Usage is left to inference from the name and filter semantics.

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