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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds real context beyond that: the four possible job states and that the result media id is available when done, which is important since there is no output schema. It doesn't mention polling cadence or what is returned on failure.

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?

A single compact sentence with zero filler, front-loading the resource and the originating tool before the state list. The parenthetical aside is short and useful.

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 two-parameter read tool with no output schema, the description covers the essentials: what states exist and that a media id comes back on success. It could say slightly more about failure output or whether the call blocks, but nothing critical 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% and both parameters are documented there, so the schema does the heavy lifting. The description only indirectly hints at job_id's origin (matching what the schema already says) and adds nothing about session_id, so the baseline 3 applies.

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 names a specific verb+resource ('Status of a Murnau VFX job'), enumerates the possible states (queued, running, done, failed), and ties the job to its originating tool lab_murnau_vfx_auftrag. That linkage separates it cleanly from the many other status siblings (lab_job_status, lab_vfx_status, lab_vfx_preset_status, lab_batch_status).

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?

It states the precondition for use — the job must have been started with lab_murnau_vfx_auftrag or in the editor — which is the key selection context. It does not explicitly say when not to use it or name the alternative status tools, so it stops short of a 5.

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