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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description is consistent with a safe read. It goes beyond annotations by explaining the semantics of the two highest-value findings — schema changed with byte-identical description, and read-only-to-destructive flips — which tells the agent why output matters, though it says nothing about rate limits, inputs' fetch behavior, or result shape beyond finding categories.

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 core purpose and the use case are front-loaded, and the finding definitions earn their place by justifying the tool's existence. Slightly long — the 'no npm equivalent' aside is persuasive rather than operational — but no sentence is pure filler.

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?

With no output schema, the description compensates by naming the categories of findings returned, which is the essential return-value context. It stops short of describing the response structure or ordering, but for a three-param read-only diff tool this is close to complete.

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 description coverage is 100% with three required params, so the schema already documents server, fromVersion, and toVersion. The description adds no syntax or semantic detail beyond what the schema provides, matching the baseline 3 for fully-covered schemas.

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 opening clause states a precise verb (drift detection) plus resource (an MCP server's tool contract) plus scope (between two versions). The two named finding types (SILENT DRIFT, PRIVILEGE WIDENING) sharpen what this tool uniquely produces and differentiate it from generic siblings like compare or compat.

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?

It gives a clear trigger: 'Use before upgrading a server an agent depends on.' That is actionable timing guidance, but it offers no explicit when-not condition or named alternative among the many sibling tools (compat, compare, diff_surface), leaving the agent to infer disambiguation.

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