search_contacts

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

No annotations are provided, so the description carries the full burden. It doesn't disclose matching semantics (partial vs exact, case sensitivity), result shape (does it return one contact or many?), or whether a phone number requires a country code — meaningful gaps for a lookup tool.

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?

Front-loaded one-sentence purpose followed by an Args block. Brief and readable, though the Args restatement partially duplicates the only schema property and adds little.

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 single-parameter read tool with no output schema and no annotations, the basics are covered but the agent still can't predict result shape (single vs list), match granularity, or how phone-number queries are normalized.

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 0%, so the description must compensate. It does say the single 'query' parameter matches contact names OR phone numbers, adding meaning beyond the bare string type, but it gives no format guidance for phone numbers or expected match behavior.

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?

States a specific verb and resource ('Search WhatsApp contacts') plus the two dimensions searchable (name or phone number). It's clearly distinct from sibling like get_direct_chat_by_contact or list_chats, though it doesn't explicitly name those alternatives.

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 never says when to reach for this tool versus get_direct_chat_by_contact (which also resolves a contact) or list_chats. Usage is only implied by 'search by name or phone number' with no exclusions or prerequisites.

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