add_subtitles

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

No annotations exist, so the description must carry the behavioral load; it usefully discloses no re-encoding and container-to-codec mapping. It omits write/overwrite semantics, error conditions, and .mov handling (which appears only in the schema), leaving meaningful gaps for a mutation tool.

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, front-loaded sentence packs the essential verb, resource, formats, and key constraint with no wasted words.

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?

Given a rich parameter schema and no output schema, the description is adequate for invocation, but for a mutation tool with no annotations it should ideally flag output overwrite behavior and explicitly distinguish itself from burn_subtitles.

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 the baseline is 3. The description reinforces accepted subtitle formats and adds container-codec behavior, but adds little parameter-specific meaning beyond what the schema already documents.

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 ('Embed') and resource ('subtitle track into a video container'), and the 'without re-encoding' phrase implicitly separates it from hard-burn tools. However, it does not name the sibling burn_subtitles, so an agent must infer the distinction rather than being explicitly routed.

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?

Provides implied usage (soft-subtitle embedding, accepted formats) but never states when to choose this over burn_subtitles or other subtitle/media tools, nor any exclusions. No explicit when/when-not guidance is present.

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