get_unread_count

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

With no annotations, the description carries the burden and does well: it discloses the return format ('object with a single "count" field (number)'), the optional folder_id, and the prerequisite 'Requires Outlook to be running.' This adds meaningful behavioral context beyond the 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?

The description is concise and well-structured: it opens with the purpose, then usage, return format, parameter detail, and prerequisite. Every sentence is necessary, with no redundancy or fluff.

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 simple count tool with one optional parameter, the description is complete. It covers purpose, usage, return format, and a prerequisite. No output schema exists, but the return value is clearly explained. No significant gaps.

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 schema already describes folder_id at 100% coverage, so baseline is 3. The description adds value by explaining the optional nature and directing to list_folders for obtaining folder IDs, which is a helpful cross-reference beyond 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?

Clearly states the tool's function: 'Get the count of unread emails' with scope across all folders or a specific folder. It differentiates from siblings like list_emails by explicitly noting it's a 'quick check without fetching full email lists'.

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?

Provides clear context: 'Use this for a quick check without fetching full email lists.' It also references list_folders for obtaining folder IDs, guiding the user to a related tool. It doesn't name alternative tools explicitly but implies when this tool is appropriate.

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