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

Annotation Contradiction: The tool is marked readOnlyHint=true, but the description states setting mark_read:true 'flag returned events read so the next call only shows newer ones' — a state-changing side effect. This directly contradicts the read-only annotation. Despite the description being transparent about the behavior, the contradiction warrants a score of 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?

Four sentences, front-loaded with the core function, no redundancy. Each sentence contributes either return-shape details, filtering options, state-mutation semantics, or a direct link alternative. Properly 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?

The description covers return shape, filtering, state mutation, polling suitability, and an external endpoint. For a tool with 5 optional parameters and no output schema, this provides comprehensive context for an agent to decide when and how to invoke it.

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 coverage is 100%, so the baseline is 3. The description adds value by giving a concrete example for type ('sec_8k'), clarifying the 'since' format (ISO timestamp), and explaining the effect of mark_read on subsequent calls. This enriches the bare schema definitions.

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 is a specific verb+resource pairing. It clearly states the tool returns the most recent alerts with detailed payload attributes, distinguishing it from siblings like list_subscriptions (which lists subscriptions, not events) 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?

It provides concrete usage context: filtering by type (e.g., 'sec_8k') and since (ISO timestamp), mark_read behavior for pagination-like reading, and even an alternative endpoint for scripts/dashboards. While it doesn't explicitly name sibling tools to avoid, it gives clear scenarios and alternatives.

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