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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive hints. The description adds valuable context by explaining the mark_read behavior ('flag returned events read so the next call only shows newer ones') and mentioning that polls work fine. This clarifies the only mutable aspect without contradicting the readOnlyHint because it's opt-in.

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 three sentences, front-loaded with the core purpose, then quickly covers return payload, filtering, mark_read, polling, and an alternative URL. Every sentence adds value; no filler or 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, no output schema, and moderate complexity, the description covers the key aspects: what is returned (source, citation_uri, raw payload), filtering by type and time, the mark_read side effect, polling suitability, and an alternative access point. This is sufficient for an agent to select and invoke the tool correctly.

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 parameters are already fully described in the schema. The description adds beyond that by giving a concrete example for type ('sec_8k'), explaining the 'since' filter as an ISO timestamp comparison, and describing the effect of mark_read. This enriches the schema's dry 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 a specific verb+resource: 'Pull fired events from your subscription feed.' It clearly states the tool returns recent alerts written to a persisted feed, and distinguishes itself from sibling tools like list_subscriptions or recent_changes by focusing on alert events with specific metadata (source, citation_uri, raw payload).

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 context: it's for polling alerts from a subscription feed, and even mentions an alternative access method for scripts/dashboards (the direct JSON URL). It does not explicitly compare against sibling tools or state when not to use it, but the polling guidance and alternative URL offer practical usage direction.

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