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

Beyond the annotations, the description reveals important behavioral details: partial updates are supported, changes are applied separately by WhatsApp, and on a refusal the 'applied' field lists which changes took effect. This is useful, non-obvious behavior that the annotations alone do not convey.

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 four sentences with no filler. It front-loads the primary purpose, then gives usage guidance, a prerequisite, and an important behavioral note. Every sentence contributes information an agent needs.

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?

Given the tool's six parameters and output schema, the description covers purpose, which fields to change, the admin prerequisite, and the partial-application behavior. It is complete enough for a correct invocation without needing to consult external documentation.

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 coverage is 100%, so the baseline is 3. The description adds value by clarifying that optional parameters should only be passed when they need changing and that several parameters can be combined in one call. This partial-update semantic is not fully evident from the schema alone.

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 starts with a specific verb and resource ('Change a WhatsApp group's settings') and enumerates the exact settings it can modify: name, description, locked, and announce. This clearly differentiates it from siblings like wa_update_participants or wa_create_group, so an agent can select it correctly.

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 explicit usage context: pass only the fields to change, multiple fields can be changed in one call, and admin status is required when the group restricts settings. It does not name alternative tools for exclusion, but the guidance is clear enough for when this tool should be invoked.

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