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

Annotations already establish read-only, idempotent, closed-world behaviour, so the description's job is to add what those don't say. It does disclose the data source and mode-switch behaviour, but it says nothing about pagination semantics, result size, ordering guarantees across pages, or cost, despite limit/offset being the main operational controls.

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?

Purpose is front-loaded, but the body is one enormous run-on sentence with nested parentheticals that mixes return-field definitions with cap formula and hashing rules. Every clause carries information (no padding), yet the lack of structure makes it hard to scan and easy to mis-parse.

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 carries the full burden of explaining return shape, and it does so thoroughly: per-close fields, per-Agent fields under close=, and worked definitions of cap, door and check. Only pagination behaviour and cross-segment caveats for callers are left thin.

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 schema already documents every parameter including the segment archival note and the sort/state coupling. The description restates the close= behaviour and the state meanings, adding modest interpretation but no syntax or edge-case detail beyond the schema.

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?

Opens with a specific subject and scope: 'Who could become established at each close of a segment, from the public close records', and the close= paragraph names the alternate grain (one row per Agent). That is enough to separate it from list_established/list_never_established, though the dense domain jargon (eligible_raw, door, check) makes the purpose slower to grasp than it should be.

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?

Supplies one usage sentence ('Use it to see each close's intake, its cap and who was eligible but not admitted') and one content exclusion ('Never a pending row, seal or score'). It never names a sibling tool or states when to prefer this over list_established or get_epoch, so alternative selection 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.