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

Annotations already mark this as destructive=true, readOnly=false, and idempotent=false, so the description benefits from adding that the operation stops unread display and does not alter templates. However, it does not discuss reversibility, permission requirements, or what happens when bulk clearing affects many items. Given the annotation coverage, a 3 is appropriate rather than a contradiction.

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 core behavior is front-loaded and the action list is compact. It is not bloated, though the phrase 'mark notifications_read items' is slightly awkward and the action separator formatting is a bit terse. Overall it is appropriately sized for the tool's complexity.

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 five-parameter mutation tool with no output schema, the description covers the main behavioral distinction between actions and what does not change. The remaining details, such as return format and failure handling, are either less necessary or already covered by annotations and the schema. It is complete enough to support correct invocation.

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 80%, so parameters are largely documented in the schema itself. The description adds useful action-level semantics for acknowledge versus acknowledge_all, including the required eventIds/all distinction. It does not expand on mode or agentId beyond what the schema already documents, so baseline 3 is reasonable.

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 uses a specific verb and resource: 'Mark notifications_read items as handled so they stop showing as unread.' It distinguishes the tool from notifications_read and adds the scoping fact that templates are not modified. An agent can immediately tell this is a write/acknowledgement tool rather than a read tool.

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 splits the two supported actions and states what each needs: acknowledge for specific event IDs, acknowledge_all for all unread items optionally scoped to an agent. It does not spell out when not to use the tool or mention the need to fetch IDs via notifications_read first, but the action choice is clear.

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