search_users

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the agent knows this is a safe read operation. The description adds useful behavioral context about the name-based search limitation (only returns contacts), which isn't captured in annotations. However, it doesn't describe other behavioral aspects like pagination, rate limits, or authentication requirements.

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?

The description is appropriately sized with two sentences that each add value. The first sentence states the purpose and search criteria, while the second adds important behavioral context. However, the parenthetical repetition in the first sentence is slightly redundant.

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 read-only search tool with full schema coverage and clear annotations, the description provides adequate context. It covers the purpose, search criteria, and an important behavioral constraint. The main gap is the lack of output format information, but since there's no output schema, this is a minor limitation.

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 the schema already fully documents all 4 parameters. The description adds minimal value beyond the schema by mentioning the same search criteria and the name-based search constraint (which is already in the 'names' parameter description). Baseline 3 is appropriate when the schema does the heavy lifting.

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 clearly states the verb ('search') and resource ('Users'), specifying the search criteria (phone numbers, email addresses, ids, or names). It distinguishes from the sibling tool 'search_user' (singular) by emphasizing 'multiple Users' and the ability to search by multiple criteria types.

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 provides clear context for when to use this tool (searching users by specific identifiers) and includes an important constraint for name-based searches (only returns contacts). However, it doesn't explicitly state when NOT to use it or mention alternatives like 'get_user' or 'search_user' for different use cases.

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