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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so safety adds nothing. The description does contribute real behavioral context by mentioning the SEC Form D filing and that `flags` indicate what to verify before trusting a round, which signals data provenance and quality caveats. It says nothing about pagination, caching, or freshness guarantees.

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 scope, with no filler. The second sentence about `flags` is compact and adds value rather than repeating the title.

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 an output schema present and safety covered by annotations, the description needn't explain return values, and it doesn't. But for a seven-parameter filtering tool with near-zero schema descriptions, the definition leaves the agent guessing about time window, sorting, and amount filtering semantics.

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 only 14%: only `investor` is documented in the schema, while days, sort, limit, stage, sector and min_amount_usd are bare. The description adds no meaning for any of them (no window semantics, no sort behavior, no amount units), so it fails to compensate for the coverage gap.

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 resource precisely (recent funding rounds of AI and developer-tool startups) and enumerates the payload fields, so an agent knows exactly what it gets back. It does not explicitly say 'list/query' or contrast itself with siblings like latest_news or company, so it stops just short of a 5.

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?

There is no statement of when to call this versus latest_news, company, or search, and no exclusions or prerequisites. Only the word 'Recent' hints at a default window, leaving the routing decision to the agent.

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