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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds useful behavioral context beyond that: group_by switches from listing to counting, and buyer names and MOIC are included in results. Pagination limits and output shape are not discussed.

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 compact sentences with the scope and primary filters front-loaded, followed by the mode-switching group_by detail and one concrete example. No filler or repetition.

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 10-parameter read-only tool with no output schema, the description covers the main modes, filters, and returned fields well. Minor gaps remain around pagination behavior and the optional gp restriction, but nothing essential to correct invocation is missing.

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 every parameter is already documented in the schema. The description adds a little meaning by explaining entry-year ranges and group_by counts, but does not clarify the gp restriction or year/year_from/year_to precedence beyond what the schema already states. Baseline 3 is appropriate.

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 (search) and resource (PE investments/deals) with an explicit scope (cross-firm, ALL European PE firms). The capitalized 'ALL' clearly distinguishes it from single-firm siblings like gp_portfolio and gp_exits, letting an agent tell it apart without opening schemas.

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 clear context: use it for cross-firm investment search and counting via group_by, with a concrete example question. It does not explicitly name alternatives like search_companies or state when not to use it, but the scope is well implied.

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