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

Annotations already declare readOnlyHint, idempotentHint and non-destructive behavior, so the safety profile is covered. The description adds domain-specific behavior: the engine folds one close at a time, close= expands added/removed address lists, and a CSV endpoint is exposed. That is useful context beyond the annotations, though return format/pagination is not discussed.

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?

Two sentences, no obvious padding, and the core purpose is front-loaded. The grammar is slightly dense ('engine fold one close at a time') and the usage sentence comes after the CSV path, but overall it is compact and readable.

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 read-only, idempotent reporting tool with no output schema and full schema description coverage, the description supplies the key semantics: what each close row contains, what close= changes, and where the CSV lives. Minor gaps around pagination or exact CSV shape are acceptable given the annotations and schema.

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%, so the baseline is 3. The description adds meaning for the close parameter by saying it enables the added and removed address lists, which is output-shape information not fully spelled out by the schema. It does not add much for sort, dir, or segment, keeping it from a 5.

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 resource ('standing changes per close of a segment') and enumerates the fields returned (before, added, removed, after, net), which tells an agent what it gets. It does not explicitly differentiate itself from siblings like get_standing or list_governance_standing, so it stops short of a 5.

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 final sentence gives a clear use case: 'Use it to see who became or stopped being established at each close.' That is a real context cue for selection. There is no explicit when-not guidance or named alternative, so it is not a 5.

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