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

readOnlyHint=true already tells the agent this is a safe read, so the safety burden is covered. The description adds the upstream endpoint (GET /v1/user/search/list), which is marginal context, but says nothing about return shape, ordering, pagination defaults, or result-size behavior. With annotations carrying the safety profile, this is an adequate-but-thin 3.

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 scoping. The trailing endpoint reference is harmless but is filler that does not help an agent decide or invoke. Overall tight.

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 zero-required-parameter read tool with full schema coverage and annotations that declare read-only behavior, the description covers what is needed to call it. No output schema exists, so return values need not be explained, though a note on pagination semantics would have completed the picture.

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 all four parameters (email, limit, offset, displayName) are already documented in the schema. The description restates the two filter fields but adds no format, matching, or default-value detail beyond what the structured data provides. 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?

The description gives a specific verb and resource ('Search/list users') and names the two filterable fields. It is clearly distinguishable from all siblings, which cover incidents, teams, and on-call data rather than users. The only minor ambiguity is the dual 'Search/list' framing, which leaves it slightly unclear whether the call is a keyword search or a plain enumeration.

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 states that filtering by email or display name is optional, which implies the no-argument case returns everything. However, it never says when to reach for this versus a related lookup, nor any exclusion or prerequisite. Usage is implied rather than explained.

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