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

The annotations declare readOnlyHint=true and destructiveHint=false, but the description states that setting mark_read:true 'flag[s] returned events read so the next call only shows newer ones,' implying a persistent state mutation. This contradicts the readOnlyHint annotation, so the score is 1 per the rubric.

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 concise and well-structured, front-loading the core action and including only relevant details: filters, mark_read behavior, and the HTTP alternative. Every sentence earns its place without 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?

With 5 optional parameters and no output schema, the description covers the return payload (source, citation_uri, raw event payload), filtering semantics, and the mark_read side effect. It omits pagination and explicit ordering beyond 'most recent,' but that is a minor gap for a feed-reader tool.

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 describes all 5 parameters with 100% coverage. The description adds an example type ('sec_8k') and explains the follow-up effect of mark_read, but these are marginal enhancements over the schema's own descriptions. Baseline 3 is appropriate.

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 opens with 'Pull fired events from your subscription feed,' which uses a specific verb and resource, and clarifies the scope as 'most recent alerts the evaluator has written.' This clearly distinguishes it from sibling tools like list_subscriptions and recent_changes.

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 clear usage context: polling works, mark_read affects subsequent calls, and there's an alternative URL for scripts. However, it does not explicitly name sibling tools or state when not to use this tool, so it stops short of a 5.

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