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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and open-world nature are covered. The description adds nothing about behavior beyond the read semantics, and an output schema exists to carry the return shape, so a baseline 3 is appropriate.

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?

A single terse sentence with the resource and key front-loaded and no filler. It is appropriately sized, though it sacrifices detail for brevity.

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?

For a simple single-id lookup with full schema coverage, a covered safety annotation set, and an output schema, the description is minimally sufficient. It leaves the agent to infer the search-vs-item routing, which is the main remaining gap.

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?

There is exactly one parameter with 100% schema coverage, including a concrete example ('294471-37'), so the schema fully documents it. The description only restates that the id identifies the investor, adding no syntax or format meaning beyond 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?

The description names the specific resource (PitchBook investors dataset record) and the key (investor id), so an agent can tell this is a single-record lookup. It does not explicitly distinguish itself from siblings like datasets_pitchbook_investors_search or datasets_pitchbook_investors_facets, but the 'item' vs search/facets distinction is inferable from the name.

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 use this tool versus the sibling search/facets tools, nor any prerequisite or exclusion. Usage is only implied by the tool name.

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