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

With no annotations, the description carries the behavioral burden and does meaningful work: it discloses graceful partial failure ('each service degrades independently if its creds are missing') and outlines the returned content including a human summary. It omits auth prerequisites, rate limits, and any ordering/timeout behavior.

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 tight sentences, front-loaded with the composite scope, followed by the failure-mode caveat. No filler and nothing repeated from structured fields.

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 composite tool with no output schema and no annotations, the description covers inputs' degradation behavior and enumerates what the snapshot contains. It could say more about the shape of the fused output (e.g., how the human summary is delivered) but is largely sufficient to call correctly.

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 description coverage is 100% and both parameters are documented there, including the SENTRY_PROJECT env fallback. The prose adds no additional meaning about urgency filtering or project scoping, so this sits at the baseline.

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 a specific aggregate resource and states exactly what it fuses: top unresolved Sentry issues, active PagerDuty incidents, and current on-call. The 'COMPOSITE' framing and 'fused into one snapshot' distinguish it from single-source siblings like sentry_recent_issues without needing the schema opened.

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?

'A right-now on-call picture' clearly conveys the scenario in which this tool applies (live incident triage), so an agent can pick it over the point-source siblings. It stops short of explicit when-not conditions or naming alternatives like sentry_recent_issues for narrower needs.

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