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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds useful context beyond that: deterministic computation, no external calls, no auth required, and error-envelope behavior for unsupported fields instead of raising.

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 dense paragraph with the routing rule front-loaded after the identity clause; nearly every clause carries information. Minor redundancy ('startup valuation' repeated, awkward double 'valuation valuation') costs it a point.

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 values need not be explained, and sibling differentiation is strong. However, the core payload — which fields 'arguments' accepts — is deferred to an unexposed schema, leaving an agent unable to construct a valid call without the native tool's definition.

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% for the single 'arguments' parameter, so baseline is 3. The description reinforces that arguments must match the referenced tool's schema and that unsupported fields return an error, but since that referenced schema is not exposed, it cannot tell the agent which fields are valid.

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 the tool and frames it as a startup valuation capability, but it never states what 'valuaton_probability' actually computes (e.g. probability-weighted/scenario valuation). It is largely a restatement of the name plus routing context, so the agent learns scope but not the specific computation.

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?

It explicitly states when to use it ('only for the startup valuation valuation_probability case that the native tools do not handle') and names six concrete alternative tools to prefer. This is a textbook when/when-not/alternatives statement.

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