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

The annotations are all false and provide little safety context, so the description carries most of the burden. It adds useful behavioral detail: API keys are transient and never persisted, entitlement checks are respected, and language instructions are applied. However, it omits that this makes an external network call and says nothing about response behavior or error conditions.

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 short sentences with no filler. The core action is front-loaded, followed by security-relevant behavior and constraints. Every sentence contributes information without redundancy.

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 tool with 18 parameters, no output schema, and sparse annotations, the description is far too brief. It covers API key handling and entitlement checks, but it omits how to construct a request, what the response looks like, what adapterMode options mean, and how failures are surfaced. An agent would struggle to call this tool correctly without external knowledge.

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%, and the description provides no meaningful parameter-level guidance. With 18 parameters including adapterMode, baseUrl, endpoint, authMode, and responseTextPath, the description fails to compensate for the schema's lack of explanations.

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 states a clear action ('Run') and a specific resource ('a Poly-Glot prompt against a developer-supplied model endpoint'). This distinguishes it enough from sibling tools like get_custom_model_capabilities or validate_custom_model, though it does not explicitly name 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?

There is no guidance on when to prefer this tool over siblings such as validate_custom_model or get_custom_model_capabilities. The description implies it is for executing prompts, but it does not state exclusions, prerequisites, or alternative selection criteria.

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