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

Annotations already declare non-destructive, idempotent, open-world behavior, so the bar is lower. The description adds meaningful context beyond that: it is a partial patch requiring at least one field, and it disambiguates the photo update path. It still omits auth/permission requirements and what the mutation returns.

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?

Four short sentences, front-loaded with the verb and the partial-update rule, and each sentence carries distinct information (constraints, alternative tool). No filler.

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?

No output schema exists, but for a patch-style mutation the description covers the essential calling semantics: partial update, at-least-one rule, field limits, and the sibling photo tool. Auth requirements and required identifiers are left implicit, slightly limiting 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?

Schema coverage is 75%, so the schema already documents most parameters. The description's limits for about (139), description (512), and websites (max 2) largely restate what the schema descriptions already give, adding little beyond the structured fields.

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?

Specific verb (update) plus resource (public business profile of a phone number) that an agent can distinguish from siblings. It also explicitly carves out the photo case by naming that the profile photo has its own tool, which differentiates it from whatsapp_business_profile_photo_update.

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?

States the partial-update contract clearly (send only fields to change, at least one required) and routes the photo case to a sibling tool. It does not contrast against whatsapp_business_profile_get or state prerequisites, so it falls short of explicit when/when-not guidance.

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