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

The readOnlyHint annotation already tells the agent this is a safe read. The description adds that results include contact details, which is modest but real return information. It says nothing about result limits (max_results exists but default/pagination behavior in practice is unstated), and nothing about whether the search is fuzzy or exact, which matters 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?

Two short sentences, front-loaded with the core action, no padding. Slightly under-loaded rather than bloated, but nothing needs deleting.

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 simple read tool, annotations cover safety and the schema covers all parameters, so the remaining burden is small. Still, the description never resolves the overlap with contacts_directory_search, which is the most likely source of mis-invocation in this sibling set.

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 100%, so query, account, and max_results are all self-documented. The description's field list (name, email, phone) is essentially a subset of the schema's query documentation and adds no new meaning; baseline 3 applies.

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 Google Contacts by name, email, or phone. That is clear and actionable. However, the sibling set includes gws-mcp__contacts_directory_search and gws-mcp__contacts_list, and the description never says how this personal-contacts search differs from a directory search, leaving likely ambiguity for the agent.

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?

No when-to-use guidance at all. For a search tool sitting next to contacts_directory_search, contacts_list, and contacts_get, the description should say when to search versus list versus fetch by ID. Nothing here routes the agent.

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