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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds two useful pieces of context beyond that: the API-key prerequisite and the returned field set (review status, health status, call count, credits earned). It omits pagination and result-size behavior, which keeps it from a 5.

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 English sentence is tight and front-loaded, with the returned fields enumerated efficiently. The Chinese sentence, however, is a full restatement of the same content rather than an addition, effectively doubling the description length without adding information.

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, zero-parameter, read-only listing tool with annotations covering safety, this is close to complete: it states the auth requirement and previews the response fields, compensating for the absent output schema. Only pagination or result-size expectations are 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?

The tool takes zero parameters, so there is nothing for the description to disambiguate. The baseline for a no-parameter tool is 4, and nothing in the text creates confusion about invocation.

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 ('List the cards') plus a clear scope ('published under the current API key'), which distinguishes it from discovery-oriented siblings like mycel_discover. It does not explicitly name the sibling it is not, so it falls 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?

Usage is implied by the scope phrase 'under the current API key' — an agent can infer this is for inspecting its own listings rather than browsing the marketplace. However, no explicit when-to-use or when-not guidance is given, and alternatives such as mycel_discover or mycel_update_card are never referenced.

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