add_subtitles

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

With no annotations provided, the description carries the burden of behavioral disclosure. It explains the return value (status message) and the optional styling behavior, but it does not disclose potential side effects such as whether the original video is modified or whether the output file is overwritten. This is adequate but leaves some behavioral ambiguity.

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 well-structured as a docstring with a one-sentence summary followed by an Args list and Returns section. Every sentence provides necessary information about parameters or return behavior, with no redundancy or filler. It is appropriately sized for the tool's complexity.

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?

The description covers all parameters, the return value, and the core behavior, making it sufficient for a tool with a nested object parameter. It lacks explicit mention of error handling or edge cases, but given the output schema is present and the tool is relatively straightforward, it is nearly complete.

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?

The schema has 0% description coverage, but the description comprehensively documents all parameters in the Args section, including the supported keys for the font_style dictionary. This adds significant meaning beyond the raw schema, which only lists property names and types without any descriptions.

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 clearly states the tool's function: 'Burns subtitles from an SRT file onto a video, with optional styling.' This is specific, uses a clear verb-resource pair, and distinguishes it from sibling tools like 'add_text_overlay' or 'add_image_overlay' by focusing on SRT subtitle burning rather than generic text or image overlays.

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?

The description implies the tool is used when subtitles need to be embedded into a video, but it provides no explicit guidance on when to choose it over alternatives like 'add_text_overlay' or when not to use it. There is no mention of prerequisites or exclusions, so the usage context is clear but not fully delineated.

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