Search contacts

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

Beyond the read-only/idempotent annotations, the description discloses that the same person can be returned twice across accounts, that each copy has its own id and address book, and that merging would break a later contacts_update. This is exactly the kind of non-obvious behavior an agent needs to safely use the results.

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?

Three sentences with no filler: the first states the purpose and matching behavior, the second explains the account-scoping option, and the third delivers the critical duplicate-result caveat. Each sentence earns its place and the most important usage detail is front-loaded.

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 low-complexity read-only search with rich annotations and fully documented parameters, the description covers the core scenarios, the all-accounts exception, and the dangerous edge case around duplicates. No output schema is present, but the description provides enough return-related context (duplicate copies with distinct ids) to avoid misuse.

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 schema already documents all three parameters with descriptions, so the baseline is 3. The description adds meaningful semantic detail: query covers nicknames and organisations, omitting account triggers a global search, and max results are per account when searching all. This exceeds 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 opens with a specific verb and resource ('Find people in the account address book') and enumerates the fields the query matches (names, nicknames, email addresses, phone numbers and organisations), so an agent can tell this is a query-based search rather than a plain list or fetch. It doesn't explicitly compare against sibling tools such as contacts_list or contacts_get, so it stops short of a top score.

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 gives concrete scoping guidance: omit 'account' to search every connected address book at once, and it warns that duplicates across accounts are intentional and that merging them would make contacts_update edit the wrong record. It does not state explicit when-not-to-use rules or name alternatives, but the context is clear.

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