get_usage_stats

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

No annotations are provided, so the description must carry the full transparency burden. It discloses the output metrics but does not explicitly state that the operation is read-only or has no side effects. The read-only nature is strongly implied by 'Get' and the nature of statistics, but not made explicit.

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 two sentences long, front-loaded with the tool's purpose, and each sentence provides useful information. No wasted words or redundant content.

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 zero-parameter, read-only statistics tool, the description adequately covers the return value (call counts, success rates, average latency) and scope (this session). No output schema exists, but the description explicitly lists the key metrics, making the tool's behavior clear enough for an agent to invoke 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?

The tool has zero parameters and an empty input schema. There is no parameter burden for the description to carry, so the baseline score of 4 applies. The description appropriately focuses on what the tool returns rather than parameters.

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 uses a specific verb and resource: 'Get usage statistics for this MCP server session.' It clearly states what is returned (tool call counts, success rates, average latency), and this distinguishes it from the ENS-focused sibling tools, none of which relate to usage statistics.

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 establishes a clear context: this tool reports usage statistics for the current MCP server session. It does not explicitly mention alternatives or exclusions, but there are no competing sibling tools with similar functionality, so the use case is sufficiently clear.

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