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

Annotations already cover read-only/idempotent safety. The description adds meaningful behavior beyond them: only approved rounds are counted, category defaults to equity, and country filtering restricts to companies headquartered there. It does not disclose sort order direction or tie-breaking, but the counting semantics are a genuine addition.

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?

Three sentences, ranked criterion front-loaded, no filler. Dense but every clause carries filtering or default information; only the country format restatement is redundant with the schema.

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 exists, yet the description conveys what is returned (a ranking of investors by approved-round count) and how filters affect it. Adequate for a simple read-only ranking tool whose annotations cover the safety profile.

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 all five parameters (from, to, limit, country, category) are already documented. The description restates the country slug/ISO and equity-default details rather than adding new syntax, so it earns only the baseline.

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 verb+resource+ranking criterion: investors ranked by the number of approved rounds they appear in. An agent can distinguish this from list_funding_rounds or funding_summary, but no sibling is named explicitly to disambiguate against get_investor_scorecard.

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?

The description explains filter semantics (country scoping, category default) but gives no when-to-use or when-not-to-use guidance. Nothing tells the agent how this ranking differs from get_investor_scorecard or largest_rounds.

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