title_card

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

With no annotations, the description carries the behavioral burden and does disclose two meaningful traits: the silent audio track (so it composes with audio-bearing clips) and bundled-font rendering (no system font dependency). It doesn't mention that the tool writes a file to disk, what happens with output path collisions beyond the schema's overwrite flag, or what it returns, leaving real gaps for a file-producing operation.

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, zero filler, front-loaded with the core action and output shape, followed by the two facts an agent most needs (silent audio for compositing, bundled font). Nothing repeats structured fields.

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 an 11-parameter, 100%-documented schema with no output schema, the description covers the non-obvious behavioral facts (silent track, bundled font, pipeline integration). The main omission is the return value / output file location, which an agent must infer from the schema's output parameter and the overwrite flag.

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%, so all 11 parameters including defaults and constraints are already documented. The description adds only implicit semantics (text is centered, background is solid) and no format or behavior detail beyond the schema, so the baseline of 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 and resource ('Generate a standalone title card') and immediately specifies what the output is: centered text on a solid background with a silent audio track. This differentiates it from generic compositing siblings like overlay or callout, and the assemble_highlights reference makes its role in the pipeline unambiguous.

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 gives a clear integration path ('use assemble_highlights to stitch it in') and explains why the silent audio track exists, which is the main usage nuance. It does not state when not to use this tool (e.g. instead of overlay/callout for text on existing footage), so it falls short of full when/when-not guidance.

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