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

Annotations already cover safety (readOnlyHint=true, openWorldHint=false), yet the description adds real operational context the annotations cannot: a 1-credit cost per successful call, the CAD-cent conversion, and the fact that schema-invalid input is rejected before billing. It omits failure modes beyond schema rejection (e.g. what happens on unsupported type strings), which keeps it short of a 5.

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?

Two sentences, front-loaded with purpose, then return shape, then billing/validation. Every clause carries information an agent would otherwise lack; nothing is padding.

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?

There is no output schema, and the description compensates by naming the returned keys. Cost and rejection behaviour are disclosed. What's missing is anything about limits on the params map (size, nesting depth) or error output, which matters for a nested-object input tool.

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% and the params property already documents the 'type[:extra][!] description' grammar, enum syntax, array item types, and the '!' required marker. The description only alludes to 'a compact parameter spec' without adding syntax or edge-case detail, so it does no more than the schema already does.

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?

States a specific verb ('Builds'), the resource ('tool definitions'), the three target platforms (Anthropic, OpenAI, MCP), and the input form ('compact parameter spec'). The return shape { anthropic, openai, mcp } further disambiguates it from siblings like mcp-config-validate or openapi-lint, which validate rather than generate.

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?

Usage is implied by the input contract: you have a parameter spec and want paste-ready definitions. But there is no explicit when-to-use/when-not, and no pointer away from near-neighbours such as mcp-config-validate (validate an existing config) or slash-command-scaffold. The agent must infer the boundary.

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