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

Annotations already declare readOnly/idempotent/no open world, so the safety profile is covered. The description adds a genuinely useful behavioral fact the annotations cannot: amounts are never converted across currencies, which changes how an agent should interpret results.

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?

One sentence, front-loaded with the ranking behavior and the currency caveat. Nothing is pad or redundant.

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?

No output schema, and the description omits defaults for year/per_currency, the sort order, and response shape. The key interpretive caveat (no currency conversion) is present, so it is adequate but not complete for a ranking tool.

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% with only two optional params (year, per_currency), so the schema carries the load and a baseline of 3 applies. The currency note tangentially explains per_currency's meaning but adds no default value or range guidance beyond the schema's '≤200'.

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?

Names a specific resource (disclosed equity rounds) plus the differentiator (ranked largest, per currency). That ranking scope separates it from list_funding_rounds and most_active_investors without needing the schema.

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?

Usage is implied by the name and description ('largest' ranking), but there is no explicit statement of when to prefer this over list_funding_rounds, funding_summary, or most_active_investors, and no exclusions or prerequisites.

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