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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description's job is lighter. It adds meaningful behavioral context: visibility is not a full public roster and depends on whether the caller is a normal participant or an organiser. This is valuable detail beyond the schema and annotations, with no contradiction.

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 compact and well-structured: a clear purpose sentence first, then the important visibility nuance, then a single actionable pointer to a related tool. Every sentence earns its place and nothing is 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 simple read-only list tool with full schema coverage, the description covers purpose, visibility rules, caller-role behavior, and a follow-up tool reference. Nothing essential is missing for an agent to select and invoke it correctly.

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 100%, so event_slug, page, and page_size are already fully documented. The description adds no additional parameter-level meaning beyond the schema. This is the baseline 3 for high schema coverage.

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 starts with a specific verb and resource: 'List participants at an event who are looking for a team.' It adds a clear visibility distinction (normal caller vs organiser) that clarifies the exact scope. It doesn't explicitly name sibling tools to differentiate from, so it stops short of a 5.

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 clear context about when the tool is useful and describes how results vary by caller role. It also points to team_matchmaking_teams as the follow-up tool for AI-ranked suggestions, which is a useful alternative routing cue. It doesn't state explicit when-not-to-use conditions, so not a 5.

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