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

Given the readOnlyHint annotation, the bar is lower, but the description adds useful operational context: the response is identical to the MCP resource, the tool should be used only once, and it should be preferred over the resource. These details go beyond the annotation and help set agent expectations.

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 somewhat verbose and mixes multiple instructions without clear separation. The first sentence states the core purpose well, but the subsequent sentences about ordering and alternatives could be more tightly organized.

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 parameterless, read-only tool, the description provides sufficient context: what the tool returns, how to sequence it with other resources, and its relationship to alternatives. The lack of an output schema makes the description's naming of the identical resource helpful.

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 has zero parameters, so the baseline is 4. The description correctly adds no parameter details, as there is nothing to explain beyond the schema's empty properties.

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 clearly identifies the tool's purpose as providing the full core source code of the HMR library. It distinguishes itself from siblings like unit tests and basics by emphasizing 'core only.' While the phrasing is a noun phrase rather than an explicit verb, the intent is unambiguous.

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 provides explicit sequencing: call learn-hmr-concepts first, read hmr-docs://about, and use the tool only once. It also states a preference for this tool over the named MCP resource. However, it references 'learn-hmr-concepts' while the sibling list shows 'learn-hmr-basics,' which could be an inconsistency.

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