ledger_stats

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

With no annotations provided, the description carries the full behavioral burden. It does disclose the analytical dimensions returned (repeat counts, sign flips, cluster duplicates, error rate), implying a read-only aggregation, but says nothing about output format, scoring semantics (e.g. what 'cross-family' means), or cost.

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?

A single sentence that front-loads the intent and enumerates the metrics. Somewhat flowery phrasing ('going in circles') costs a little precision but the sentence is compact and earns its length.

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?

For a zero-param, no-annotation tool with no output schema, the description is reasonably complete: it tells the agent what the tool reports. It stops short of clarifying how to interpret 'cross-family' or the return shape, which would fully close the 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?

The tool takes zero parameters, so there is nothing to document; the baseline for a parameterless tool is 4.

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 concrete metrics (repeated evaluations, sign flips, near-duplicate clusters, cross-family error rate), which tells the agent this is a reporting/aggregation tool over some ledger. However, the framing 'how much has been tried, and where the session is going in circles' is impressionistic, and it never states a clear verb+resource or distinguishes itself from siblings like evaluate or gate.

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?

There is no guidance on when to call this versus fingerprint, evaluate, or gate, no prerequisites, and no exclusions. The agent must infer usage entirely from the metric list.

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