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

Annotations only tell the agent this is a non-destructive, non-idempotent, closed-world mutation. The description adds the visual content but not what happens on repeat calls (stacking vs replacing an existing HUD), whether it is removable, or whether it is tied to a clip range.

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?

It is a single efficient sentence with the core action front-loaded, and no filler. However, the long feature enumeration consumes the whole description while more decision-critical information (range, colour, replacement behavior) is omitted, so the space is not optimally spent.

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 15-parameter creative mutation with no output schema and near-zero schema documentation, the description is thin: it never explains the start/end range, colour/accent usage, or whether multiple HUDs coexist. An agent can guess the intent but not call it confidently.

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?

With 15 parameters and only 7% schema description coverage, the description must carry the burden and largely does not. It maps loosely onto the boolean flags (rec, timecode, brackets, crosshair, grid) and hints that tl/tr/bl/br are corner labels, but accent, colour, id, start and end—including their units and defaults—are left entirely unexplained.

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 gives a specific verb plus resource ("Adds configurable frame furniture") scoped to a program window and enumerates the concrete variants (corner labels, rec indicator, timecode, brackets, crosshairs, grid). This makes it distinguishable from generic siblings like add_overlay or add_text, though it never explicitly names which sibling it is not.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives in a very crowded add_* family (add_overlay, add_editorial_graphic, set_screen_frame, add_title_card). The agent must infer from the feature list alone whether this is the right tool.

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