Modal MCP Server

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

With no annotations provided, the description carries the full burden. It discloses return content ('URL and full metadata') which compensates for the missing output schema, but omits operational details like read-only safety, error cases (e.g., invalid job_id), or rate limits.

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 with zero waste: first establishes the operation and identifier, second discloses the return payload. Perfectly front-loaded and appropriately sized for a single-parameter lookup tool.

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 tool's simplicity (1 parameter, flat structure) and lack of output schema, the description adequately covers the essential contract: what it fetches, how to identify it, and what data comes back. Minor gap regarding error handling or read-only status.

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 coverage is 100% and the schema already documents that job_id is 'returned by modal_render'. The description references the parameter ('by job_id') but does not add semantic depth beyond the schema's existing documentation.

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 ('Get'), identifies the exact resource ('Modal render job'), and scopes it to a single entity 'by job_id'. This clearly distinguishes it from siblings like modal_render_list (plural) and modal_render (likely creation).

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?

While it doesn't explicitly name alternatives, the keywords 'single' and 'by job_id' provide clear contextual guidance that this is for targeted retrieval of a known job, implicitly contrasting with modal_render_list for browsing and modal_render for creation.

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