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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely non-obvious context beyond the annotations: counts are STATUTORY, derived from history notes rather than observations, which warns the agent about what the numbers mean. Return shape is partly described, though not full behavioral traits like pagination or how `since_year` interacts with the by-year breakdown.

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 one-line summary, then usage, then an important caveat and sibling routing. Every sentence earns its place with no padding.

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?

An output schema exists, so return values need not be spelled out, and the description still previews the return shape. The main residual gap is the undocumented `top`/`since_year` parameters against 0% schema coverage, but overall the definition is sufficient for correct invocation.

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 description coverage is 0% for 3 parameters, so the description must compensate. It clarifies only `chapter` (omit for corpus-wide); `top` and `since_year` are left entirely to their names, with no explanation of the default count, ordering, or whether `since_year` filters all returned aggregates.

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 states a specific measure (legislative churn/amendment counts) on a specific resource (an NC statute chapter), and explicitly contrasts itself with amendment_history and pending_changes. An agent can distinguish it from every sibling without opening a schema.

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?

It gives a concrete use case ('which parts of Chapter 14 keep changing'), an explicit corpus-wide mode ('Omit `chapter` for a corpus-wide view'), and names the two alternative tools with the conditions that select them (per-section vs. upcoming text).

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