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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world behavior. The description adds useful behavioral detail beyond the annotations: it preserves existing rules, adds one clean group per choice, includes a shared content-signal line, and returns text without modifying the site.

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 front-loaded with the usage condition, then explains inputs, gives a compact example, and states the return value. Every sentence earns its place and there is no unnecessary repetition.

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?

The tool is simple and fully covered: annotations carry the safety profile, the schema documents all four parameters, and the description explains the generated output and that no site is changed. Nothing material is missing for correct invocation.

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%, so the schema already documents the parameters, defaults, and enum values. The description reinforces the three group choices and mentions the optional existing robots.txt, plus an example, but does not add much beyond what the schema provides.

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 resource: writing robots.txt with AI bot choices. It clearly distinguishes the tool from the sibling check tools by emphasizing that it returns a complete robots.txt to paste and does not change any site.

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 first sentence gives a clear when-to-use condition: the user wants to allow or block AI training, AI search, or assistant bots and needs the robots.txt lines. It does not explicitly name the sibling check tools as alternatives, but the generation-vs-checking distinction is clear.

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