Gemini Speak Tool

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

No annotations are provided, so the description carries the full behavioral burden, and it discloses nothing beyond the basic action: not the output audio format, length limits, latency, or whether results are returned inline or as a file. The presence of an output schema softens this slightly, but the description adds no behavioral context.

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 with zero waste. It is arguably under-specified rather than verbose, but structurally sound and easy to scan.

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 tool is simple, the output schema exists, and the input schema is fully documented, so the minimum needed to invoke it is present. Still, the absence of any usage routing or behavioral detail leaves it only marginally adequate for an agent choosing among many sibling tools.

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 both the required 'text' and the 'voice' parameter (with its default and full voice list) are already documented in the schema. The description adds no syntax, format, or length guidance beyond that, 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?

States a specific verb+resource ('Convert text to speech'), which is unambiguous on its own. However, it offers no differentiation from siblings like gemini_list_voices_tool or gemini_dialogue_tool, and the name 'speak_tool' is not echoed anywhere in the description.

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 guidance on when to use this tool versus the voice-related siblings (notably gemini_list_voices_tool, which would logically precede calls here). No prerequisites, no mention of when a voice should be specified.

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