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

The description contradicts the readOnlyHint annotation by revealing that setting mark_read:true will flag returned events as read, altering the persisted feed. This is a state-changing behavior, yet the annotation claims the tool is read-only. The contradiction is severe and overrides any additional behavioral context the description provides.

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 primary action. Every sentence adds value: data payload, filtering options, mark_read behavior, polling, and an alternative endpoint. No filler or repetition.

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?

Despite lacking an output schema, the description fully covers the return values (source, citation_uri, raw payload), relevant parameters, and usage context. It even explains the side-effect of mark_read and the availability of an HTTP endpoint. For a simple read tool, this is highly complete.

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 enriches this by explaining the semantics of mark_read ('flag returned events read so the next call only shows newer ones') and giving a concrete type example ('sec_8k'). It also clarifies the 'since' parameter as an ISO timestamp, adding meaning beyond the schema's terse descriptions.

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' – a specific verb and resource that clearly states the tool's core function. It further details what each alert carries and how filtering works, making the purpose unmistakable and distinct from siblings like list_subscriptions or 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 clearly sets the context: this is for reading alerts from the subscription feed, and explicitly notes that polling works fine. It also provides an alternative (the direct HTTP endpoint) for scripts/dashboards, implicitly directing agent use to this tool. It does not explicitly contrast with sibling tools, but the context is unambiguous enough for a 4.

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