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

Annotations already establish the safe read-only, idempotent profile, and the description adds substantial non-structured behavior: the companies-only construction and how individuals surface in not_itemised, the instruction to report scope.share_itemised, the national_portfolio=not_available caveat against over-reading holdings, UK-only scope, and a 10-credit cost. These are exactly the operational constraints an agent cannot get from the annotations or schema.

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-loads the deliverable and what the rank contains before the caveats, and every warning (companies only, share_itemised, national_portfolio, UK-only, cost) is actionable. It is dense and slightly long, and some of the field enumeration duplicates the output schema, which keeps it out of 5 territory.

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 analytics tool with an output schema present and no required params, the description covers the things the schema cannot: data-construction limitations, reporting obligations, geographic scope, and cost. The only gap is input semantics, which is scored separately.

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% and there are 6 parameters, so the description carries the full burden — but it only explains `strategy` (rank owners of units the preset points at) and gestures at strategy_overrides. The area-defining pair (lad_code vs postcode_district), limit, and the min_units=2 threshold are completely unaddressed, leaving the most consequential inputs for scoping the area undocumented.

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 specific resource and deliverable ('who owns the stock in an area, ranked as an approach list') and enumerates exactly what the rank contains (units held, value/equity, years held, short-lease and on-market counts, company status, ranking signals). This is clearly distinguishable from sibling ownership tools like ownership_by_company or sourcing_owners, which do not produce a ranked approach list.

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?

Gives a concrete usage trigger ('pass a strategy to rank the owners of only the units that preset points at — short-lease flats in a borough, say') and hard exclusions (companies only; private individuals are never listed and must not be inferred). It stops short of naming a sibling alternative to use instead when the caller wants individual owners or non-UK data, which keeps it below a 5.

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