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

Annotations only state readOnlyHint=true; the description adds meaningful context about the free count vs. the paid named-firms result and the Understanding requirement. However, it does not disclose return shape, pagination, or behavior on unknown slugs, so behavioral transparency is partial.

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?

The description is compact and starts with the core purpose before moving to pricing and entitlement details. Every sentence carries useful information, though the repeated 'UNDERSTANDING' branding and pricing URI add minor noise for an agent primarily deciding what the tool does.

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 one-required-parameter read-only lookup, the description gives enough to invoke the tool: pass a provider/company slug to get backing VC firms. However, there is no output schema and no description of the response format, empty-result behavior, or error cases, leaving some ambiguity.

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?

The schema leaves 'slug' undocumented, and the description compensates by identifying it as the provider/company slug. The 'context' parameter is already well described in the schema, so the description adds fair but not complete parameter-level value given 50% schema coverage.

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 clearly states the tool's purpose: it returns which VC firms back a given provider/company identified by slug. The phrase 'reverse portfolio edge' hints at how it differs from portfolio-oriented siblings, though it does not explicitly name those alternatives.

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 explains pricing and entitlement conditions but not when to choose this tool over siblings like find_vcs, vc_portfolio, or get_vc. An agent must infer the use case from the phrase 'reverse portfolio edge' rather than receiving explicit when-to-use or when-not-to-use guidance.

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