Microsoft 365 MCP Server

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, covering safety and flexibility. The description adds minimal behavioral context ('retrieve a list'), which doesn't contradict annotations. However, it misses opportunities to explain pagination behavior (implied by 'top'/'skip'), search/filter capabilities, or that it returns a list rather than details—though these are somewhat inferable from parameters.

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 a single, efficient sentence with zero wasted words. It's front-loaded with the core action ('retrieve'), though it could be more specific. Every word earns its place, making it highly concise and well-structured for quick scanning.

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?

Given the tool's complexity (12 parameters, no output schema) and rich annotations, the description is minimally adequate. It states the basic purpose but lacks context on output format, error handling, or integration with siblings. The schema and annotations cover safety and parameters, but the description doesn't fully compensate for the missing output schema or provide holistic guidance.

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 description coverage is 100%, with all 12 parameters well-documented in the schema (e.g., 'top' for limiting items, 'search' for phrases). The description adds no parameter-specific information beyond the generic 'list of attachment objects,' so it doesn't enhance understanding of individual parameters. Baseline 3 is appropriate given the schema does the heavy lifting.

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?

The description 'Retrieve a list of attachment objects' clearly states the verb ('retrieve') and resource ('attachment objects'), but it's vague about scope and doesn't distinguish from sibling tools like 'get-mail-attachment' (which retrieves a single attachment) or 'list-mail-messages' (which lists messages rather than attachments). It lacks specificity about what 'attachment objects' means in this context.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing a messageId), differentiate from 'get-mail-attachment' for single attachments, or explain when filtering/pagination parameters are appropriate. The agent must infer usage from the schema alone.

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