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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely non-obvious behavior: the tool is free, and results are plan-gated (Platinum gets the full list, other plans see only the first few buildings). It does not explain how that truncation interacts with the cursor, which is the one remaining behavioral gap.

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 tight sentences with no filler; the key constraint (ownership type) is front-loaded before the plan limitation. The one-word 'Free.' opener is a fragment but functions as a useful up-front qualifier rather than waste.

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-value documentation is not required, and the description covers the prerequisite, the ownership-type distinction, and plan gating. However, for a tool whose results are truncated by plan, the pagination contract (what cursor does, whether it recovers the hidden buildings) is left entirely unexplained.

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%, so the description carries the full burden, yet it only vaguely indicates that personKey comes from search_nyc_owners. It says nothing about personKey's required pipe-delimited format, its length bounds, or the existence and purpose of the cursor parameter for paginating beyond the truncated result set.

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 verb (lists) and resource (NYC buildings linked to a person) plus the added dimension it returns — ownership type (owner of record vs. through a company). It explicitly ties itself to the sibling search_nyc_owners, which is exactly the tool an agent would otherwise confuse it with.

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 phrase 'linked to a person from search_nyc_owners' tells the agent this is a follow-on lookup whose input comes from that search tool, which is clear routing context. There is no explicit when-not guidance or statement of what to do if the portfolio is empty, so it stops short of a 5.

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