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

With no annotations, the description carries the full burden, and it does disclose the output form (a self-contained HTML file, not a URL or a persisted tile) plus the intended follow-up action of saving and opening it. That is real behavioral value. It omits whether generating a preview has any side effects or persistence, whether the inputs must already exist, and any permission or size constraints.

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 tight sentences, front-loaded with what is produced, followed by the actionable next step. Nothing is redundant. It could be tightened slightly, but every clause carries information.

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?

No annotations, no output schema, a nested object parameter, and zero parameter documentation leave substantial gaps for a five-input tool. The description explains the return artifact well but says nothing about what the inputs must contain or how the declarative and code authoring modes differ, which is exactly the complexity an agent needs resolved here.

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 0% across five parameters, including a nested 'spec' object and an 'authoring' enum, so the description is the only possible source of parameter meaning. It supplies none: 'code', 'name', 'slug', 'spec', and the declarative-vs-code choice are all unmentioned. At most it hints that the inputs collectively describe 'this calculator', which is not enough to call the tool confidently.

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 states a specific verb and artifact: 'Generate a self-contained HTML file that renders this calculator as a real tile.' That is far more concrete than a restatement of the name, and the 'test before submitting' phrasing implicitly separates it from create_calculator/update_calculator. It stops short of naming any sibling explicitly, so the agent must infer the boundary itself.

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?

'Open it in your browser to test before submitting' implies this is a pre-submission validation step, which is genuine usage context. However, it never says when to prefer this over create_calculator, fork_calculator, or validate_build, nor what happens if you skip it. Usage is implied rather than stated.

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