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

The second sentence restates the annotations nearly verbatim (readOnlyHint, idempotentHint, destructiveHint, openWorldHint), which earns no credit since it duplicates structured data. What does add value is 'Free' (a cost signal) and 'reflects live external market state', which explains why values may change between calls despite idempotency.

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 useful payload (status fields, cost) is front-loaded, but roughly half the text is a redundant annotation echo that an agent already has in structured form. Trimming that would leave a tighter, stronger definition.

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?

There is no output schema, so the description must sketch the return content, and it does so by naming the four categories of status returned. An agent knows what to expect and what it costs; only the exact shape of the response remains unstated.

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 of 4 applies. The description correctly implies no inputs are needed by presenting the call as a plain status read.

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 concrete resource (live engine status) and enumerates its contents: mode, watchlist, scan freshness, scorecard summary. That is specific enough to distinguish it from the data-returning siblings (mnemos_arb_scan, mnemos_bars, mnemos_options_scan), though it never explicitly says how it relates 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?

The only usage signal is the leading 'Free.' There is no statement of when to call this instead of a sibling, no precondition (e.g. call before a scan to confirm freshness), and no exclusion.

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