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

Annotations declare readOnlyHint:true, but the description explicitly says mark_read:true 'flag[s] returned events read so the next call only shows newer ones'—a persistent side effect. This directly contradicts the read-only annotation, so despite rich behavioral detail, the contradiction forces a score of 1.

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 front-loaded with the purpose and uses a few well-structured sentences. Each sentence contributes useful details (return fields, filtering, mark_read behavior, HTTP alternative), though the last sentence about the registry URL could be seen as slightly tangential for the tool's core use.

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 5 optional parameters and no output schema, the description adequately explains the return items, filtering options, mark_read side effect, and even provides an external endpoint. It doesn't cover limit or unread_only, but the schema fills those gaps; the contradiction with annotations keeps it from a 5.

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 schema already covers all 5 parameters with descriptions, so baseline is 3. The description adds value by giving an example type ('sec_8k'), explaining the since parameter as an ISO timestamp, and clarifying that mark_read causes the next call to return only newer events—semantic nuance beyond the schema.

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 a specific verb ('Pull') and resource ('fired events from your subscription feed'), and clearly states the return payload. It distinguishes itself from siblings like list_subscriptions and recent_changes by focusing on fired alerts from the evaluator's feed.

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 gives clear context: it's for pulling recent alerts, supports polling, and mentions an HTTP alternative for scripts/dashboards. However, it doesn't explicitly contrast with sibling tools or state when not to use this tool, so it falls just short of full guidance.

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