createAgent

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

Annotations only indicate readOnlyHint=false and destructiveHint=false. The description goes beyond by explicitly flagging that voicemail detection is access-gated and requires requesting access, which is critical behavioral context. It also lists supported features, giving a fuller picture of what the tool can do.

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 main description is concise — two sentences plus a focused callout about voicemail access. The voicemail note is redundant with the schema's voicemail description, but it's blockquoted and doesn't bloat the core text. Overall well-structured and fast to parse.

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 has one complex requestBody parameter and no output schema, yet the description doesn't mention what the response contains (e.g., the created agent object with ID). It covers the input side well but misses return-value expectations, which is a gap for a create operation.

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% with detailed property-level docs (e.g., model enum, voice fields, end_call behavior). The description adds only a high-level list of supported config areas, which doesn't materially improve on the schema. Baseline 3 is appropriate since the schema carries the parameter-meaning burden.

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 'Create a new agent with the provided configuration' — a specific verb plus resource. It enumerates the configurable areas (transcriber, model, voice, etc.), which distinguishes it from sibling tools like getAgent, updateAgent, and deleteAgent.

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 clearly implies use for creating a new agent, with context about the full configuration capabilities. It doesn't explicitly name alternatives, but sibling tool names (e.g., updateAgent) make the distinction obvious. The voicemail access-gate note provides prerequisite guidance for that specific feature.

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