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

Annotations already specify readOnlyHint=true, destructiveHint=false, idempotentHint=true. The description adds further behavioral context by detailing the return values (status, message, tool_id, upgrade_url) and provides an example call, which is well beyond what annotations offer.

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 four sentences, front-loaded with the main purpose. Each sentence adds value: purpose, parameter explanation, return details, and example. There is no fluff or redundancy.

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?

Given the tool's simplicity (one parameter, read-only check), the presence of an output schema, and clear annotations, the description fully covers what an agent needs to know. It explains what the tool does, what input to provide, and what to expect in return.

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 input schema covers the parameter with 100% description coverage, so baseline is 3. The description adds an example and reiterates the parameter's purpose, which provides marginal additional value but does not significantly enhance understanding beyond the schema.

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 'Check MCPize subscription status for a DataNexus tool,' which uses a specific verb and resource. None of the sibling tools are related to subscription status, so it is well-distinguished.

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 clearly states the required parameter and how to use it ('Pass the tool the user is asking about'). However, it does not explicitly mention when not to use this tool or list alternatives, which would be helpful but is not critical given its unique purpose.

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