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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the safety profile is covered; the description still adds 'Nothing is stored and the API is not called' and lists the response contents, which is worthwhile given there is no output schema. It does not mention input size limits (the 1.5M character cap) or performance/validation-failure behavior.

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?

Front-loaded with the verb and result, followed by when-to-use and a safety note; every clause carries information. The enumerated output list is slightly long but earns its place because no output schema exists.

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 one-parameter, read-only preview tool with no output schema, the description covers what goes in, what comes back, side-effect guarantees, and the motivating use case. An agent has everything needed to call it correctly and interpret the result.

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?

With a single required parameter at 100% schema coverage, the schema already does the work. The description adds only marginal meaning — that the input is raw text and that a custom GPT Action schema is a typical example — which is useful framing but largely duplicates the schema's 'JSON or YAML' note.

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 opens with a specific verb and resource — 'Validate an OpenAPI 3.0/3.1 schema ... and show the MCP tools it converts to' — and enumerates exactly what the preview contains (tool names, method/path, hints, detected auth, errors). This clearly separates it from the sibling tools (a retirement guide and a client-setup helper).

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 explicit trigger conditions: 'Use this when someone wants to migrate a custom GPT Action or turn an OpenAPI spec into an MCP server.' That is clear context for selection. It stops short of naming when-not-to-use conditions or pointing at the siblings as the alternative path after a preview.

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