source_status

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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description adds substantial value on top: it discloses the exact fields returned, the presence of error history, and a staleness heuristic for interpreting the output. It doesn't cover refresh cadence or whether the classifier status is live vs cached, but the diagnostic context is genuinely useful.

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?

Front-loaded with the classifier state, then the per-source field list, then a single diagnostic sentence that earns its place by telling the agent how to read the data. Slightly dense in the middle enumeration but no wasted filler.

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?

With no output schema and no annotations describing returns, the description carries the burden of explaining the payload, and it does so reasonably: it lists the reported fields and gives a staleness interpretation. It stops short of describing the structure/shape of the response, but is adequate for a zero-arg status tool.

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?

Zero parameters, so the baseline is 4 — there is no parameter surface for the description to compensate for.

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 names a concrete resource (sources) and enumerates exactly what is reported: classifier active state, on/off, last success, last error, newest announcement, and record counts. It's a monitoring/status tool, clearly distinct in intent from case/announcement siblings, though it never explicitly differentiates itself from them.

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?

Usage is only implied — the diagnostic note that a source whose newest announcement hasn't moved 'has quietly stalled' hints at when to consult this (health checking), but there is no explicit when-to-use, prerequisite, or alternative tool guidance.

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