add_narration

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

With no annotations, the description carries more weight. It discloses the gTTS implementation and timeline placement behavior, but does not mention side effects (e.g., whether it replaces other narration) or error conditions. This is useful context but not exhaustive.

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?

Compact description with the main purpose front-loaded. The 'IMPORTANT' instruction is generic but not verbose; still concise overall.

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 the simple two-parameter schema and presence of an output schema, the description provides enough context to understand when and how to use the tool. Minor gaps around side effects are acceptable given the output schema.

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 descriptions already fully document both 'text' and 'lang' parameters. The description adds no additional semantic information beyond restating that text is spoken.

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 identifies the action ('Generate and add'), the resource ('text-to-speech narration audio track'), and distinguishes from siblings like add_background_music by specifying narration specifically.

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 usage by noting the audio plays at the timeline point where the tool is called, giving clear context for placement. However, it doesn't explicitly compare against alternatives like add_background_music.

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