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

With annotations declaring readOnlyHint=false and destructiveHint=false, the description adds meaningful behavior: partial patch semantics, nested upserting, declarative platform-tool replacement, and the caveat that enable_voicemail_detection is intent-only. It does not cover permissions, atomicity, or error behavior, but it is substantially more transparent than the annotations alone.

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 front-loaded, dense, and free of filler. Two sentences cover the update model, the two most complex fields, and the important empty-array detach case without repetition.

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 mutation tool with nine parameters, nested objects, no output schema, and sparse schema coverage, the description is adequate but incomplete. It covers core patch behavior and the trickiest fields, but does not explain the opaque config blocks or operational details such as permissions and failure modes.

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 only 11%, so the description must compensate for many undocumented parameters. It explains voice_settings and platform_tools, but leaves assistantId, name, voiceId, description, llmConfig, chatConfig, and voiceConfig largely or entirely unexplained, especially the opaque nested config objects.

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: "Patch an assistant." It is clear this is a partial update rather than create, get, list, or archive. However, it does not explicitly name sibling tools or contrast itself with them.

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 provides useful update semantics: "Only supplied fields change; nested config blocks are upserted." It also explains declarative behavior for platform_tools, including that an empty array detaches all. It does not state when to choose this tool over assistants_create or other siblings, nor does it give prerequisites or exclusions beyond the field-level behavior.

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