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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely new behavior: what the response carries (primary-series coverage, latest value, pagination, source hashes, run id, caveats) and the incomplete-universe caveat, which is important for an open-world lookup.

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?

Four compact sentences with no filler, opening with the framing question and then moving to scope, output, and usage. Slightly less front-loaded than ideal because the usage cue arrives last, but every sentence earns its place.

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 must carry return-value information, and it does (coverage, latest value, pagination, hashes, run id, caveats). Combined with the explicit scope exclusion, an agent has enough to call it correctly, though the exact shape of a match record is still unspecified.

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 100%, so limit, offset, query, entity_type and response_format are already documented. The description's list of row classes loosely echoes the entity_type enum values but adds no syntax or filtering detail beyond the schema; a baseline 3 is appropriate.

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 names a specific verb (find/search) and resource (holder names and stable ids in the hosted TIC Major Foreign Holders archive), and it enumerates the row classes it scans. It is clearly distinguishable from siblings such as treasury_tic_holder_history, treasury_tic_compare_holders, and treasury_tic_rank_holders, which operate on already-identified holders.

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?

"Use this before history or comparison when a label is uncertain" gives an explicit trigger condition plus the sequencing relative to other tools. It also bounds scope ("not the complete TIC country universe"), but the sibling tools are not named outright, so the routing is inferred rather than spelled out.

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