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

No annotations exist, so the description carries the full burden. It usefully discloses the newest-first ordering and the scope of returned data, but says nothing about permissions/auth, rate limits, or how pagination pairs with limit. Adequate but incomplete for a read tool with zero structured hints.

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 sentences, front-loaded with the resource and data scope, then the routing rule. Zero filler; every clause 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?

With no output schema, the description correctly enumerates the return fields and ordering, which is what an agent needs to judge relevance. The only gap is behavior around limit/pagination, a minor omission for this simple 3-parameter lookup.

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 67% and the schema itself documents company_id, its companyid alias, and limit bounds/defaults. The description adds no parameter detail at all — the listed fields (deal size, type, valuation) are outputs, not inputs — so it neither compensates for the coverage gap nor repeats 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?

States a specific resource (private-company funding-round and M&A deal history) with the fields returned (deal size, type, VC round, pre/post-money valuation) and sort order, and explicitly contrasts itself with a sibling (/investors). An agent can distinguish this from tengu_v3_private_markets_company without opening a 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?

Gives explicit trigger phrasing ('when did X last raise / at what valuation / who acquired it') and names the alternative tool (/investors) with the condition that selects it ('who participated'). Nothing 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.