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

Annotations already declare destructiveHint=false and idempotentHint=true, and the description reinforces this with 'Nothing is deleted' plus describes the visible effect ('clearing the unread badge'). That effect is genuinely useful context beyond the annotations, though the no-deletion note partially restates destructiveHint=false.

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?

Two short sentences, front-loaded with the action and scope, then the effect. Every sentence earns its place with no filler.

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?

A zero-parameter bulk mutation with rich annotations and no output schema needs little else. The description covers action, scope, side effect, and non-destructiveness, which is fully adequate for this complexity level.

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?

There are zero parameters, so the schema carries no semantic burden and there is nothing for the description to disambiguate. Baseline 4 applies for a no-param tool.

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?

States a specific verb and resource ('Mark every notification as read') with clear scope ('every') that distinguishes it from the singular mark_notification_read sibling. It stops short of explicitly naming that sibling, but the scope word does the differentiation.

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 word 'every' implies bulk usage versus the single-item variant, but the description never explicitly says when to use this instead of mark_notification_read or list_notifications. Usage is implied rather than stated.

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