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

Annotations already declare readOnlyHint and idempotentHint, so safety is covered. The description does add useful non-obvious context: it returns disabled tools as well as enabled ones, and it is free, which matters given a pricing.quote sibling exists. It stops short of describing output shape, auth requirements, or ordering, so it is modest added value rather than rich disclosure.

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 short sentences with zero filler, and the payload contents are front-loaded ahead of the cost note. 'Free.' is terse but carries real decision value for an agent weighing sibling tools.

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 zero parameters and no output schema, the description carries the return-value burden and does list the returned items. It is nearly complete, missing only whether discovery must precede other calls and what format the URLs or boundary data take.

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?

The tool takes zero parameters, so the baseline is 4 and there is no parameter meaning the description needs to compensate for. Nothing in the schema is left unexplained.

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 gives a specific verb ('Return') and enumerates exactly what comes back: enabled and disabled tools, their security boundary, and canonical discovery URLs. That is clearly distinct from xguard.preflight, xguard.pricing.quote, and xguard.web.fetch, though it does not explicitly name those siblings as alternatives.

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?

There is no explicit when-to-use or when-not-to-use guidance; the agent must infer from 'canonical discovery URLs' that this is a starting point. It never states whether this should be called before xguard.preflight or how it relates to the other siblings.

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