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

Annotations declare destructiveHint=true and idempotentHint=true, and the description adds exactly the right context beyond them: the prior job is detached from the project rather than deleted, its media survives, and no credits are spent on the update. It also states the overwrite semantics, consistent with the idempotent hint instead of contradicting 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?

Opens with the core action and effect, then the scope constraints. No sentence is redundant; even the long exclusion list is load-bearing because it prevents the agent from routing editing/media-to-media work here.

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 7-parameter mutation tool with an output schema and full annotation coverage, the description supplies the necessary usage envelope, destruction semantics and cost note. The residual gap is parameter-level detail (tab, model_name, project_id), which is minor given the structured fields available.

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 only 43%, so the description must compensate; it names prompt, model, aspect ratio and duration but adds no syntax or constraints beyond the schema (duration's model-specific allowed values, ratio format, and the tab/model_id vs model_name distinction are untouched). Partial compensation for the coverage gap, so a baseline 3.

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 and resource ('Overwrite the saved widget settings') plus which fields are affected, and positions the tool in the workflow ('to a prepared project before generating'), which cleanly separates it from prepare_media_project and generate_media. An agent can identify what this does 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?

Explicitly names the supported case (text-to-image / text-to-video prompts) and enumerates a long list of excluded workflows (uploaded/attached/reference images, editing, background removal, upscaling, try-on, image-to-video, media-to-media). This is textbook when/when-not guidance with nothing left to inference.

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