contacts

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

Consistent with readOnlyHint=true and adds context annotations do not carry: matching is substring-based, results are lightweight pointers rather than full records, and Contacts requires Automation access. It stops short of noting match limits, ordering, or case sensitivity when many substring matches occur.

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?

Two short sentences, front-loaded with the action and match rule, then the return shape, then the permission and sibling routing. No sentence is 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?

An output schema exists, so return-value explanation is optional and the description's one-line summary is sufficient. Permission requirement and the write alternative are covered; only behavior under many matches (truncation/paging) is left unaddressed for a lookup that can return large result sets.

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 0% (the single `name` property has no description), so the description must compensate, and it does: it tells the agent the value is matched as a substring rather than exactly. Case sensitivity and whether org names are also matched remain unstated.

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 (find), resource (contacts), and match semantics (substring on name), plus the shape of the return (id + name/org pointers). It also names the sibling it is not (create_contact), so an agent can distinguish it without opening any schema.

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?

"Read-only" plus "See create_contact to write" gives an explicit read-vs-write routing rule between the two contact tools. It does not address whether this is the right choice when the agent only knows an email/phone rather than a name, which is a real limitation given name is the sole parameter.

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