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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is covered. The description still adds real value by disclosing the possible account states (connected, reauth_required, unavailable), which warns the agent that a listed account may not be usable for downstream calls.

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?

Three short sentences, all front-loaded: what is listed, how to consume the output, how to add an account. No filler and no repetition of the title or annotations.

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?

An output schema exists, so return-value detail need not be spelled out, and annotations cover the safety profile. With no parameters, the definition supplies exactly the missing pieces: what the listing yields and how its identifiers feed the M365/Teams tool family.

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?

Zero parameters, so there are no semantics to explain; baseline is 4. The description correctly implies this is an unfiltered listing, matching the empty schema.

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+resource ('List the Microsoft 365 accounts connected on this computer') and enumerates exactly what each entry contains (upn, id, display name, default flag, state, permissions). This distinguishes it from nearby siblings such as list_accounts, list_email_accounts, and connect_m365_account.

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?

Explicitly routes the agent downstream: use the returned email or id as the `account` parameter of the M365 and Teams tools, and use connect_m365_account to add one. Clear positive context and the add-alternative, but no explicit when-not-to-use guidance or note about the empty-result case.

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