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

The annotations already establish read-only and non-destructive behavior, and the description adds meaningful context beyond them: it is free, an unknown id returns an error, download links expire, and image payloads are capped at 2 MB. This is useful behavioral detail for an agent deciding whether and how to call it.

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 front-loaded with the return shape, then usage guidance, then behavioral constraints. It is compact and every sentence adds distinct information.

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?

Even though an output schema exists, the description covers the important states, link expiry, error behavior, and intended usage versus siblings. Nothing needed to invoke it correctly 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 coverage is 100%, so the sole id parameter is already documented as an 'rnd_ id of the render'. The description reinforces the id's meaning but adds no format or handling details beyond what the schema provides, making the baseline 3 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 precise verb and resource ('Returns the current state of a render') and enumerates the key state fields. It explicitly distinguishes itself from render and convert_to_pdf by noting those tools already return this state for their own output.

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?

Gives explicit when-to-use cases: following a render started with wait=false, or obtaining a fresh link after expiry. It also explicitly says when not to use it because render and convert_to_pdf already return the same data.

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