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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=false, so the safety profile is covered structurally. The description adds nothing beyond that – no mention of required mailbox authorization, duplicate-name behavior, or what is returned – which meets the minimum bar given annotation coverage.

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 the action first and rationale second; nothing is wasted. Slightly more context could have been added without bloat, so it is efficient but not maximally informative.

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 two-parameter creation tool with annotations covering safety and no output schema, the description is adequate but thin. It omits the mailbox prerequisite, does not address the undocumented 'name' parameter, and does not indicate that the created calendar's identifier is likely needed for follow-up calls such as create_outlook_calendar_event.

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 only 50%: the mailbox parameter is well documented in the schema, but the required 'name' parameter has no description anywhere. The description says only "a new calendar" and never clarifies what the name parameter represents or its constraints, so it fails to compensate for the coverage gap.

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 and resource ("Create a new calendar"), and the name makes the Outlook variant identifiable against create_google_calendar. However, it never explicitly contrasts itself with the Google or other sibling calendar tools, so an agent must rely on the name alone.

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 clause "useful for keeping a client's or project's events separate from the default one" gives an implied use case, which is more than nothing. But there is no explicit when-to-use-vs-alternatives guidance and no mention of prerequisites such as needing a connected mailbox or how this differs from create_google_calendar.

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