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

readOnlyHint=true already covers the safety profile, and the description adds value beyond that by enumerating the exact fields returned (name, id, default status, write permission), which matters because there is no output schema. It does not mention pagination or rate limits, so it is additive but not exhaustive.

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, front-loaded with the purpose and followed by the usage routing. Every clause carries information; no filler or redundancy.

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 zero-required-parameter read-only list tool, the description covers purpose, return fields (in the absence of an output schema), and workflow positioning. An agent has everything needed to call it correctly and chain into get_calendar_events.

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 100%, so the single 'account' parameter is already fully documented, including the omit-to-use-all behavior. The description's plural 'mailboxes' and the account=... usage example echo the schema but add no new parameter syntax; baseline 3 applies.

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 (List) and resource (calendars in connected Outlook mailboxes) and even enumerates the returned fields (name, id, default, can-add-events). The 'Outlook' qualifier clearly separates it from the sibling list_google_calendars.

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?

Gives explicit when-to-use ('find a named calendar before reading it') and names the downstream alternative with concrete call syntax get_calendar_events(calendar_id=..., account=...). Nothing is left to inference for the selection decision.

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