ask_vapi_docs

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

Annotations already cover the safety profile (readOnly, openWorld, non-destructive), so the description's job is to add context, and it does: it discloses the return shape (passages plus source URLs) which no output schema documents, and the word 'current' signals live retrieval rather than cached data. It omits rate limits and how many passages come back by default, which keeps it short of 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?

Two sentences, front-loaded with the purpose and the retrieval source, with zero padding. The semicolon-joined second clause is slightly compressed but still readable.

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 two-parameter read-only lookup with full schema coverage, the description supplies the essentials: retrieval source, return content, and an implicit instruction to ground answers in the passages. Nothing critical is missing apart from guidance on competing tools.

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%, including topK bounds and a note forbidding API keys or private customer data, so the schema carries the parameter burden. The description adds no syntax, format or default guidance beyond that, making the baseline 3 correct.

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 ('Ask about current Vapi documentation') and adds what comes back ('documentation passages and source URLs'). It is clearly distinguishable from the assistant/call/simulation siblings, though it never mentions the potentially overlapping get_api_schema tool.

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 only usage instruction is 'use them to answer the question,' which concerns consuming the results rather than when to select this tool. There is no statement of when-not to use it and no routing to alternatives such as get_api_schema for raw API schema lookups.

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