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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the safety profile is covered. The description adds value beyond annotations by listing the returned profile fields (display name, email, UPN, job title, mobile phone), which helps the agent predict output without an output schema.

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: the first states the action and results, the second gives the intended use. No redundant wording or fluff; all content earns its place.

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 profile fetch, the description is complete: it identifies the data returned, the use case, and the annotations cover safety. Nothing needed for correct invocation is missing.

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?

With zero parameters and 100% schema coverage (vacuously), the schema already fully specifies inputs. The description does not need to explain parameters, and the baseline of 4 applies for parameterless tools.

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?

Name, title, and description align on a specific verb ('Get') and resource ('signed-in user's Microsoft 365 / Outlook profile'), and the description enumerates the exact fields returned. It clearly differentiates from sibling tools like outlook_get_message or outlook_list_folders, which target messages or folders rather than identity data.

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 description supplies a concrete use case ('Use to identify whose mailbox is connected'), giving clear context for when to call this tool. It does not explicitly name alternatives or exclusions, but the sibling tools are so distinct that the guidance is sufficient for selection.

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