Renders a bundled prompt template using supplied string variables and returns plain text without contacting an AI provider.
Render one bundled prompt template using supplied string variables. Returns text only and does not call an AI provider.
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | Prompt ID returned by list_prompts. | |
| variables | Yes | Exact template variables as non-empty strings. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description adds genuinely useful context beyond them: output is text only and no AI provider is invoked, which clarify the side-effect-free, local nature of the call.
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 short sentences, zero filler, with the core action stated first and the return/behavioral caveat second. Every clause 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?
Despite no output schema, the description states the return type (text only) and disclaims AI-provider invocation, while annotations cover the safety profile and the schema fully documents both parameters. Nothing essential for correct invocation is missing.
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%, so the id and variables parameters are already documented, including that variables are non-empty strings. The description's 'using supplied string variables' adds only marginal reinforcement, so the baseline 3 is appropriate.
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 (Render) and resource (one bundled prompt template) with scope, so it reads clearly against list_prompts and get_assistant. An agent can identify that this produces rendered text from a template without opening the 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 is implied by the description (render a template you have an id for), but there is no explicit when-to-use, when-not-to-use, or reference to the sibling alternatives (e.g., pairing with list_prompts to get ids). Adequate but leaves routing to inference.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.