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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered. The description contributes beyond that by enumerating the returned intelligence and noting the intake route comes with a source, which tells the agent this is a single-shot, self-contained lookup rather than something requiring follow-up calls.

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 core value and closed with the use case. The middle field list is long but each item is a distinct output the agent can rely on; no sentence is wasted.

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?

There is no output schema, so the description must carry the return-shape burden itself, and it does by listing the metrics and intake data delivered. What is missing is only marginal: no note on depth limits, staleness, or behaviour for an unknown investor_id.

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% and the sole parameter's description already says "Investor id from search_investors." The tool description adds no format, range, or sourcing detail beyond that. Baseline 3 is appropriate when the schema fully carries parameter meaning.

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 and spells out exactly what the payload contains: deal metrics (total deals, 90-day deals, companies backed, median round size, stage mix, first/last cheque) plus the firm's intake route and source. An agent can distinguish it from search_investors, which it implicitly pairs with via the investor_id lookup.

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 an explicit decision context: "Use this for 'should we approach them and how'." That routes the agent to this tool for outreach evaluation specifically. It stops short of naming when NOT to use it or pointing at a sibling for the raw search case, so it is not a full 5.

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