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

With no annotations, the description carries the full burden and does so well: one read-only GET per API, 10s timeout promoted to a 45s re-probe for SLOW, and no answer within 45s for DOWN. It also warns that the measurement is a cached 'last measured' snapshot via generated_at, which an agent needs to interpret staleness.

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 verb+resource, then dense semantics for SLOW/DOWN and the counts.measured caveat. Every sentence carries information, though the count-denominator note is a slight detour from what the tool itself does.

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?

No output schema or annotations exist, and the description compensates by defining the status enum-like values and the measured/total count distinction. It does not sketch the overall response shape (e.g. per-API entries, nested counts), which is the only remaining gap.

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% and the single api parameter is already documented in the schema ('substring match on API name; omit for all'). The description adds nothing about the parameter, so the baseline 3 applies.

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?

States a specific resource and scope: 'the last measured liveness of free, no-key public data APIs: HTTP status and latency.' An agent immediately knows what returns and from where, and the sibling tools (find_free_inference, get_offer) are clearly unrelated operations.

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 implied (check current health/liveness before relying on an API) but never stated explicitly, and no when-not-to-use or alternative is named. Since the siblings are unrelated tools there is little to route between, so 3 is defensible rather than 2.

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