outlook_list_events_delta

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

The annotation already indicates readOnlyHint=true. The description adds useful behavioral context: explains the delta token mechanism, first-call requirements, and the meaning of is_deleted and has_more fields. No contradictions.

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 compact (4 sentences plus example) and front-loaded: purpose first, then usage guidance, then example, then additional notes. Every sentence adds unique value with no redundancy.

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 complexity of a delta endpoint and the absence of an output schema, the description covers the key behaviors (paginated result, is_deleted tombstones, has_more flag). It could be slightly more explicit about the response structure (e.g., that it returns event objects), but is largely sufficient.

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 0%, so the description carries the full burden. It explains start/end (required on first call, ISO 8601), delta_token (used subsequently), but does not describe page_size. This covers 3 of 4 parameters with meaningful context.

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 explicitly states it lists 'calendar event changes within a window since the last call,' which is specific and actionable. It clearly distinguishes from the sibling tool outlook_list_events by positioning this as the delta/change-tracking variant.

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 explicit guidance: 'Use this for polling/recurring agents — typically 10x cheaper than outlook_list_events after the first call. Use outlook_list_events for one-shot queries.' This directly tells the agent when and when not to use the tool.

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