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

Annotations only indicate readOnlyHint=false and destructiveHint=false. The description adds meaningful behavioral context: it marks events as included in a digest, affects only the current user/run's agent, and prevents re-notification. It does not contradict annotations and provides useful side-effect information beyond the structured data.

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 two sentences with no wasted words. The purpose is front-loaded, followed by the timing and scope constraint. Every sentence contributes useful guidance.

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, single-parameter tool with no output schema, the description covers all essential aspects: what it does, when to call it, why it is needed, and the scope of its effect. It is complete enough for an agent to invoke it correctly.

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 input schema already fully describes the single parameter (event_ids) with 100% coverage, including its type and purpose. The description does not add further semantic meaning to the parameter beyond what the schema provides, so the baseline of 3 applies.

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 clearly identifies the action ('Mark monitor events as included in a digest notification') with a specific verb and resource. It is unambiguous and distinct from the sibling mark_social_posts_notified, which targets a different resource type.

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 explicitly states when to call this tool ('after composing a Slack digest') and provides a clear rationale ('prevent re-notifying the same events'). It also gives important scope guidance (current user/run's agent). However, it does not explicitly mention alternatives or when-not-to-use, so it stops short of a full 5.

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