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

Annotations declare readOnlyHint=true, but description says setting mark_read:true flags events as read, which is a state change. This contradiction undermines transparency. Without the contradiction, the description adds useful behavioral context, but the inconsistency is critical.

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?

Description is concise at four sentences, front-loads the purpose, and each sentence adds value without redundancy. No unnecessary information.

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?

Description covers return fields, filtering, and optional mutation via mark_read. It also mentions an alternative access method. However, the contradiction with annotations slightly reduces completeness regarding behavioral expectations.

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 baseline is 3. Description adds usage examples (e.g., 'sec_8k') and reiterates parameter purposes, but does not add significant new meaning beyond the schema 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?

Description clearly states 'Pull fired events from your subscription feed' with specific verb and resource. It distinguishes from siblings like 'list_subscriptions' and 'subscribe/unsubscribe' by focusing on retrieving fired events rather than managing subscriptions.

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?

Description provides clear usage context: filtering by type and since, setting mark_read, and polling. It mentions an alternative access method (GET endpoint) for scripts and dashboards, but lacks explicit when-not-to-use guidance.

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