Create Conversions API Key (CAPI)

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds a useful security note ('store securely in server secrets'), indicating the key is sensitive. However, it does not mention important creation behavior such as whether the key value is shown only once, permissions required, or how the key should be managed beyond storage.

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 two sentences with no filler: the first states the core action and purpose, and the second adds an important operational note. It is front-loaded and every sentence earns its place.

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?

Given the low complexity (one parameter, no output schema, no annotations), the description is mostly adequate: it explains what the key is for and tells the agent to store it securely. However, it is silent on the tool's return behavior, such as whether the key is returned only at creation time, which is a meaningful gap for a credential-generation tool.

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 already fully documents the single parameter with a description and example ('Production CAPI Key'), so schema coverage is 100%. The tool description adds no additional parameter-level detail, which is acceptable but does not improve semantics beyond the baseline.

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 uses a specific verb ('Generate') and names the resource ('server-side Conversions API key') along with its intended purpose ('send conversion events directly from backend servers'). This clearly differentiates it from client-side alternatives like create_web_pixel, though it does not explicitly name sibling tools.

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 gives clear context for when to use the tool: when conversion events need to be sent directly from backend servers. It does not list alternatives or exclusions explicitly, but the 'directly from backend servers' phrasing effectively implies the server-side use case.

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