hub_presence

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

No annotations are provided, so the description carries the full burden. It discloses that agents are flagged alive/stale based on ttlMin and that the data derives from hub_heartbeat calls. However, it does not mention return format, pagination, sorting, or any side effects, leaving some behavioral aspects undisclosed.

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?

Two sentences convey the essential information without extraneous detail. The metaphorical 'fleet roster' and 'screen-scraping' phrases add flavor but are not wasteful. Slightly wordy, but every sentence earns its place.

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 tool has no output schema, so the description must explain return behavior. It successfully conveys the core purpose and the alive/stale concept, but it omits details about the exact response structure (e.g., what fields are returned, how TTL is calculated). For a simple presence tool, this is acceptable but not 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?

The input schema already describes both parameters completely (100% coverage). The description adds context about the alive/stale flag and the relationship to hub_heartbeat but doesn't provide additional semantic details beyond 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 clearly states the tool's function with a specific verb and resource: it lists every agent that has called hub_heartbeat, flagging each as alive or stale based on its ttlMin. It also distinguishes from siblings by explicitly referencing hub_brief and hub_heartbeat, making its scope clear.

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 a clear usage context: to check which agents are listening and to pair with hub_brief's queue section for delivery visibility. It implies when to use it rather than alternatives, but it doesn't explicitly state when not to use it or list exclusions, which would make it a 5.

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