Last observed access state for each data source.

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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so the safety profile is covered. The description adds genuinely non-redundant behavior: results are observations, not live probes, and the state space is broken into authentication, rate limits, availability and never-checked sources. It stops short of saying how stale an observation can be or whether the states are mutually exclusive.

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?

Three short sentences, each carrying distinct information: what is returned, the key caveat that no live probe occurs, and the categories of state. The scoping caveat is front-loaded and nothing is repeated from the title or annotations.

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 an output schema present and zero parameters, the description does not need to explain return values, and the annotation set covers safety. What remains thin is the operational framing — how the cached state gets refreshed and whether a 'not yet checked' source is actionable — but that is a small gap for a diagnostic read.

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 takes zero parameters and the schema is empty, so there is nothing for the description to disambiguate; the baseline for a no-param tool applies. No parameter-level claims are made or needed.

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 specific resource ('each data source') and the exact payload ('last observed access state'), so an agent knows it returns cached-per-source status rather than race data. It is distinguishable from the F1-data siblings by being a diagnostics read, though it never explicitly frames itself as the metadata/health counterpart to 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?

'No network probe' and 'sources not yet checked in this process' imply the tool is for checking what has already been tried rather than triggering new fetches, which is useful implied usage. There is no explicit when-to-use statement, no mention of what to do if a source is unhealthy, and no named alternative.

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