get_pending_event_count

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions 'unread events' but doesn't clarify what constitutes an event, how counts are calculated, if this is a read-only operation, or any performance considerations. This leaves significant gaps for a tool that likely interacts with event systems.

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, clear sentence with no wasted words. It's appropriately sized for a simple counting tool and front-loads the core functionality effectively.

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 event systems and the lack of annotations or output schema, the description is insufficient. It doesn't explain what 'events' are, how they're categorized as 'unread', what the return format looks like, or any error conditions, leaving the agent with incomplete context for proper tool 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?

The input schema has one parameter (sessionId) with 0% description coverage. The tool description doesn't mention this parameter at all, failing to explain its purpose or necessity. However, with only one parameter and a baseline of 3 when schema coverage is low, the score reflects minimal but not helpful parameter 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 clearly states the tool's purpose with a specific verb ('Get') and resource ('count of unread events in the inbox'), making it immediately understandable. However, it doesn't explicitly differentiate from sibling tools, as there are no obvious counting or inbox-related siblings in the provided list, so it doesn't reach the highest score.

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, prerequisites, or context. It simply states what the tool does without indicating if it's for monitoring, triggering actions, or other use cases, leaving the agent with no usage direction.

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