feed_health

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

With no annotations, the description carries the behavioral burden, and it adds valuable context: these are 'volunteer-run services with no SLA,' and 'three are queried rather than one' to compensate for outages. This explains why latency or failures may be present and why redundant queries happen. It does not explicitly state read-only behavior, but that is strongly implied by a health-check tool.

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 two sentences with no filler. The first sentence states the core result, and the second provides architectural context that explains the tool's behavior. 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?

For a zero-parameter health-check tool with no output schema, the description sufficiently explains what the tool reports and why the data looks the way it does. It could have mentioned the exact return format or source names, but that is not necessary for an agent to select or invoke the tool correctly.

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 tool has zero parameters and 100% schema coverage, so the description is not required to explain inputs. The description instead focuses on what the tool measures, which is the only parameter-relevant information needed here.

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 identifies the tool's focus: 'Per-source health: latency, failures, and whether a circuit breaker is open.' This goes beyond a tautology and names specific metrics. It doesn't use an explicit verb like 'get' or 'report,' but the meaning is unambiguous and distinct from the aircraft-focused sibling tools.

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 implies this is used for checking feed health and explains the redundancy of querying three services, but it does not explicitly state when to choose this tool over alternatives or when not to use it. Sibling names like poller_status might overlap in intent, so an explicit usage boundary would have been stronger.

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