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

Annotations already declare readOnly/destructive=false and openWorld, so safety is covered. The description adds genuinely useful behavior beyond annotations: archived records are suppressed by default, pagination via next_cursor, and the API-key access requirement.

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?

Reasonably front-loaded, but the opening sentence ('Everfit: Clients in your workspace with type, coach, groups and status') is a near-restatement of the title and partly redundant with the second sentence, diluting conciseness.

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 list tool with a full schema and no output schema, the description covers filtering, default archived behavior, pagination, and auth prerequisites. It omits upfront confirmation that only IDs/records are returned, but nothing critical to invoking it correctly is missing.

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 the baseline is 3. The description largely restates schema content (type values, archived behavior) rather than adding format, default, or interaction detail beyond what the schema already documents.

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 names a specific verb+resource ('Lists your clients') and enumerates the returned attributes (type, coach, groups, status), which is more than the tautological title. It doesn't explicitly distinguish itself from the sibling everfit_get_client, but the list-vs-get intent is clear.

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?

Gives clear operating context: tells the agent to reuse each item's client_id in other tools, notes archived clients are only returned on request, and explains cursor pagination ('Pass next_cursor back as cursor'). No explicit when-not or named alternative, so it stops short of a 5.

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