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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds a useful behavioral detail — that the query can be scoped to now or to an arbitrary timestamp — but says nothing about nesting/override precedence in on-call resolution or return shape.

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 carries the meaning with no filler. The trailing 'All Quiet: GET /v1/on-call.' endpoint reference is minor padding that earns little for an agent-selection context.

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 simple optional-parameter read tool with no output schema and full schema coverage, the description is nearly sufficient; the only real gap is sibling differentiation against allquiet_on_call_report and the other on-call override 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 description coverage is 100%, so all three parameters (teamIds, userIds, timestamp) are already documented, including the 'defaults to now' semantics. The description only restates the team/user filtering and point-in-time idea, adding no new syntax or format detail.

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 specific verb (get) and resource (who is on call) with scope detail about point-in-time queries and optional filters. However, it never distinguishes itself from the similar sibling allquiet_on_call_report, so an agent must open both to choose.

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 phrase 'optionally filtered by team/user' and the parenthetical about a given point in time imply when the tool applies, but there is no explicit when-to-use or when-not-to-use guidance, and no mention of the alternative allquiet_on_call_report.

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