vmix_title_update

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

Annotations declare destructiveHint=true and readOnlyHint=false, and the description adds useful behavioral detail beyond that: all fields validate before writing, and multiple updates are ordered but not frame-atomic. This gives the agent meaningful expectations about failure modes and transactionality. It doesn't discuss auth or exact failure behavior, but the added context is valuable given the destructive annotation.

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?

Three sentences, each earning its place: what it does, how to prepare (inspect field names), and behavioral warnings. Front-loaded with the primary action and purpose. No fluff or repetition of schema content.

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 a destructive, multi-update tool with no output schema, the description covers key concerns: field name inspection, validation-before-write, and non-atomic ordering. It doesn't explain the return value or what happens when validation fails, but the prerequisites and transactional behavior are addressed. Given the tool's complexity and the destructive annotation, this is nearly complete but not fully comprehensive.

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 0%, so the description must compensate, and it does partially: it explains the meaning of 'fields' as named text fields on a title input and hints that values are strings. It also mentions 'dry_run' exists by saying 'All fields validate before writing,' but it does not explicitly document request_id, dry_run behavior, or the format of field names. The description adds some semantic meaning beyond the raw schema but doesn't fully cover all four parameters.

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 states a specific verb and resource ('Update named text fields on a title input') and clearly distinguishes it from inspection tools by warning to inspect exact field names first. It doesn't explicitly name a sibling alternative, but the behavior is specific enough that an agent can tell it apart from vmix_inspect and other sibling tools.

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 gives implicit but clear usage context: inspect field names before updating, since GT uses .Text. It doesn't explicitly mention when not to use the tool or name alternatives, but the inspection prerequisite is a useful usage guideline. No explicit exclusion of alternatives is provided, so not a perfect 5.

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