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

Annotations already declare readOnly, idempotent and non-destructive, so the safety bar is low. The description adds real behavioral detail beyond that: the 12-partner cap, that the total partner count is still returned, and which data domains are out of scope — meaningful because there is no output schema to disclose the return shape.

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 action and return contents, with the limiting constraints (12 partners, no portfolio/theses) placed last where they belong. The field enumeration is dense but every item carries selection value.

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 no output schema, the description carries the full burden of describing return values and does so thoroughly, including caps and absences. Combined with 100%-covered parameters and read-only annotations, an agent has everything needed to call it correctly.

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 single parameter already carries a description with concrete slug/name examples. The description adds no lookup-format guidance (matching rules, ambiguity handling) beyond what the schema provides, so the baseline 3 applies.

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 and resource ('Returns one firm from the Investor Atlas') and then enumerates exactly what is returned: HQ/locations, links, latest fund, entry stages, check size bands, lead preference, sectors, partners. The closing exclusion of portfolio companies and investment theses implicitly separates it from get_mode_vc_thesis_and_criteria and from search_investors.

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 scope exclusions ('does not include portfolio companies or investment theses') hint that another tool covers theses, but neither sibling is named and no explicit when-to-use condition is stated. Usage is implied rather than directed.

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