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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely non-structured context: data provenance ('compiled from public information'), that counts appear in the response, and that stage/check size are self-reported and may be unavailable. No contradictions.

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 compact sentences: purpose first, filters second, caveats last. Every clause carries information, and the parenthetical about counts is short. Slightly dense in the middle sentence but appropriately sized with no filler.

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 does the necessary work: it names the data source, the filterable dimensions, the reliability caveat on self-reported fields, and notes that counts are returned. What is still missing is a hint at the shape of a result record (fields returned per firm/partner), which would help an agent chain into get_investor_details.

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%, so every parameter is already documented with examples and enums; the baseline is 3. The description's sentence 'Filter by firm or partner name, sector, entry stage, and headquarters or location' largely restates the schema, adding only the caveat that stage and check size are as reported by each firm.

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 ('Searches the Mode VC Investor Atlas') and immediately defines scope: a directory of VC firms and their partners compiled from public info. It also draws negative boundaries ('does not hold portfolio companies or fund performance'), which lets an agent distinguish this from get_investor_details and the thesis tool at a glance.

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 enumerates the filter dimensions, which implies how to narrow a search, but never states when to choose this tool over the sibling get_investor_details or get_mode_vc_thesis_and_criteria, nor any recommended sequence (search first, then fetch details). Usage is implied rather than guided.

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