updateAgent

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

The description adds useful behavior beyond the annotations by explaining that this is a partial/patch-like update and by flagging voicemail detection as an access-gated feature that requires account-level enablement. It does not contradict the annotations and gives the agent an important prerequisite to consider.

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 description is short, front-loaded, and contains no filler: one sentence covers the action and partial-update semantics, and one callout covers the voicemail access requirement. Every part is useful for invoking the tool correctly.

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 description covers the overall semantics and the most important prerequisite despite the tool being large and nested. Because the schema is detailed and covers all parameters, the lack of an output schema description is not a major blocker, though an explicit return-value hint would have improved full completeness.

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?

The input schema already provides detailed per-field descriptions and full parameter coverage. The tool description contributes a general partial-update rule, but it does not add new parameter-level semantics beyond what the schema already documents, so the baseline score 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?

The description clearly starts with 'Update an existing agent', naming both the action and the target resource. It also scopes the behavior with 'Send only the fields you want to change', which differentiates it from createAgent, getAgent, 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?

It provides clear usage context: use this tool when modifying an existing agent, and only include the fields that need changing. It does not explicitly name alternatives or state when not to use it, so it falls short of the most explicit possible guidance.

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