Engine Status

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

Annotations already establish read-only/idempotent, but the description adds substantial non-obvious behavior: it is not a live health check, stored errors are historical, a disabled engine is not proof of a missing key, provider balances may come from a cached lookup, and unknown limits are reported as null rather than zero or unlimited. These caveats directly prevent misreading the output.

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 purpose is front-loaded in the first clause, followed by usage and then caveats, so the ordering is sound. The middle sentence is dense and long, and the description runs as a single paragraph, but nearly every clause carries information an agent needs.

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 parameters, the description must convey what comes back, and it does: engine state, rotation order, per-capability credential requirements, counters, and quota source, plus the interpretation caveats. Nothing essential to calling or reading this tool is missing.

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, so the baseline is 4; the input schema is empty and there is nothing for the description to clarify. No credit above baseline is warranted, but there is no gap either.

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 verb+resource ('Read this server's local engine configuration') and immediately enumerates what is returned: enabled state, rotation order, per-capability access, usage counters, quota source. This cleanly distinguishes it from search_web, fetch_url, and open_dashboard.

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?

Explicit when-to-use: 'before update_engine_config for valid engine ids' and 'when you need to know which providers are active, how much quota is left or why a provider is skipped'. It also routes the agent between alternatives, noting the dashboard is the human-facing view of the same data. Nothing is left to inference.

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