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

The description explicitly states that setting mark_read:true 'flag[s] returned events read so the next call only shows newer ones,' which is a mutation of state. This directly contradicts the readOnlyHint:true annotation, creating a serious inconsistency. The description reveals a side effect that the annotation denies, so it scores 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 three sentences, front-loaded with the main purpose. Each sentence adds useful information: the return payload fields, filtering options, mark_read behavior, and the HTTP alternative. It is efficient but slightly dense, so it earns a 4 rather than a 5.

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 no output schema, the description compensates by explaining the return structure (source, citation_uri, raw payload) and the mark_read side effect. It also includes polling guidance and an HTTP endpoint alternative. Despite the annotation contradiction, the description itself is reasonably complete, though it misses details on unread_only's interaction with mark_read.

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 provides 100% descriptive coverage for all five parameters. The description adds a concrete example type ('sec_8k') and reinforces the mark_read side effect, but these are minor additions over the schema, so it stays at the baseline of 3.

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 and resource: 'Pull fired events from your subscription feed.' This clearly distinguishes it from siblings like list_subscriptions and subscribe, which manage subscriptions rather than retrieve past events.

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?

Provides clear context by stating the tool retrieves fired alerts, works well for polling, and mentions the same feed is available via HTTP endpoint for scripts/dashboards. However, it does not explicitly exclude alternatives like list_subscriptions or describe when not to use this tool, so it stops short of a full when/when-not guideline.

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