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

The description discloses a write side-effect: mark_read:true flags events as read, affecting subsequent calls. This contradicts the readOnlyHint annotation. The annotation indicates a purely read-only tool, yet the tool can mutate read state, so the description contradicts the structured metadata.

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 concise (four sentences), front-loaded with the primary purpose, and every sentence adds value: return contents, filters, mark_read behavior, polling suitability, and alternative endpoint. No redundant text.

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 what is returned, the feed context, filtering options, mark_read behavior, and even an alternative access method. It does not explicitly discuss pagination or limit usage, but the schema describes the limit parameter. The main gap is the annotation contradiction, but that is penalized under behavioral transparency.

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 description adds meaning beyond the schema by providing an example for type (e.g., sec_8k), clarifying since as ISO timestamp, and explaining the effect of mark_read on future calls. Schema coverage is 100%, but the extra context elevates it above the baseline.

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 clearly states the tool retrieves fired events from the subscription feed, with specifics on return contents and filtering. It does not explicitly distinguish from sibling tools like recent_changes or list_subscriptions, but the resource is distinct enough that the purpose is unambiguous.

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 for when to use the tool (retrieving recent alerts, polling) and even provides an alternative endpoint for scripts/dashboards. It lacks explicit exclusions or comparisons to other tools, but the usage context is well-defined.

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