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

Adds context annotations can't carry: it is free with no API key, covers 93,000+ funds, and deliberately withholds firm names and contacts. That privacy constraint and the free/no-auth claim are exactly the traits an agent needs before calling. It doesn't mention rate limits or latency, keeping it off a 5.

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?

Front-loads the free/no-key signal and the use case, then flows into mechanics, enum values, and the upsell path. Small inefficiency in restating 'asset_class is one of...' as a bare list, but 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?

With no output schema, the description correctly explains what comes back (match counts by investor type, no contacts), which is the key unknown. The gaps on industry/geography/ebitda_m are the only thing keeping it from complete.

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 0%, so the description must compensate and it only partly does: it enumerates the ten valid asset_class values (absent from the schema) and gives units for target_raise_m. It says nothing about industry, geography, or ebitda_m, leaving three of five parameters undocumented anywhere.

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 (preview investor matches), the underlying engine and dataset (DEALITHIC, 93,000+ funds/family offices/angels), and the exact output shape (counts, no names or contacts). An agent can distinguish it from request_intro and lp_match_preview without opening any schema.

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?

"Use when someone wants to be connected with investors for a raise" gives a clear trigger, and the closing sentence routes the agent to request_intro when the preview looks useful. It does not state when NOT to use it (e.g. versus lp_match_preview for LP-side queries), so it stops short of full routing coverage.

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