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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description usefully discloses the scope of the vocabulary returned, but adds nothing about caching, staleness, or how 'reviewed values' differ from open formats.

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, no filler, with the content list front-loaded. The second sentence is slightly abstract ('How Tethered Trust represents...') and could be folded into the first, but the overall size is well matched to a zero-parameter listing tool.

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?

An output schema exists, so return values need not be explained, and a parameterless read-only tool is low-complexity. What is missing is the workflow context — when an agent should consult this vocabulary before calling check_compatibility or check_fit — which the description never supplies.

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 there is nothing for the description to disambiguate; the baseline of 4 applies. The schema is an empty object and needs no compensating text.

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 enumerates exactly what the tool surfaces — compatibility standard families with reviewed values, open formats for new values, and numeric limit keys — and frames it as Tethered Trust's representation model, which separates it from check_compatibility/check_fit. It never states a verb ('list'/'retrieve') and never names a sibling, so it stops short of a 5.

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 when-to-use guidance, no prerequisites, and no mention of alternatives among the seventeen siblings. The closest thing to guidance is the domain framing sentence, which implies 'reference lookup' but leaves the agent to infer it.

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