outlook_list_calendars

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

readOnlyHint=true already tells the agent this is a safe read, so the bar is lower. The description adds one useful behavioral fact — that both primary and secondary calendars come back — but says nothing about ordering, paging, or what identifying fields (IDs, names) each entry carries, which matters since downstream tools need a calendar ID.

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 sentence with the scope qualifier front-loaded after the verb; no filler, no restatement of the tool name beyond what is needed.

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-parameter, read-only enumeration tool with annotations covering safety and no output schema to worry about, the description is nearly sufficient. The one missing piece is that the returned entries carry the calendar identifiers other tools require.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline of 4 applies. The description's parenthetical about primary + secondary calendars is a reasonable stand-in for parameter-level meaning.

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) plus the scope of what is returned (primary + secondary calendars of the authenticated user). It is clearly distinct from siblings like outlook_list_events, though it never explicitly contrasts itself with the event-listing tools an agent might reach for instead.

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?

There is no guidance on when to call this versus outlook_list_events, outlook_list_folders, or the calendar-ID-dependent creation tools. The agent must infer that this is a discovery/disambiguation step before listing or creating events.

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