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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds meaningful behavior beyond that: the 'names and ids only, no cell data' payload boundary, the most-recently-changed-first ordering, and the folder-permission scoping on results.

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?

Four short sentences, each carrying distinct information (location, ordering, return payload, query mode, access limit), with the core purpose front-loaded. No filler or repetition.

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?

With no output schema, the description correctly specifies the return (names and ids) and the sort order, and it discloses the permission-based result truncation. For a simple read-only lister this is nearly complete; only explicit sibling routing is absent.

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 only 50% — the required 'mailbox' param is documented in-schema, but 'query' is bare. The description compensates by explaining query semantics ('search by name'), adding real meaning the schema lacks; the mailbox-to-list_authorized_mailboxes path is already covered by the 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 and resource ('Find .xlsx workbooks in the user's OneDrive') with scope, ordering, and output shape. 'Returns names and ids only — no cell data' cleanly separates it from get_excel_workbook, which retrieves workbook contents.

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?

'Pass a query to search by name' implies the search-mode usage, and the access-scope note implies when results are limited. However, it never says when to use this versus list_onedrive_items, search_onedrive_items, or list_google_spreadsheets, so the agent must infer routing.

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