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

With no annotations the description carries the full behavioral burden, and 'value discarded' is genuinely useful: it tells the agent the input is not echoed or retrieved. However it says nothing about the return shape, error behavior, idempotency, or side effects for the other eight parameters.

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?

It is a single compact fragment with zero waste and the key constraint (no hyphens, 32 hex) front-loaded. It is arguably too terse rather than padded, so it reads as efficient even if under-specified.

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?

For a nine-parameter, zero-annotation tool with no output schema, the description explains only the UUID shape and the discard behavior. It never reconciles the disparate parameters (ref, city, feed, host, json, path, zone, query) or indicates what a call returns, leaving real gaps for an agent. The schema covers parameters, but the behavioral contract is thin.

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 all nine optional parameters (including their 'discarded after check' notes). The description adds nothing about which parameter maps to this UUID check, so the baseline 3 applies.

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 fragment 'UUID no-hyphen 32-hex' specifies the exact resource format being checked, which is more than a tautology, but it never states the verb — whether it validates, normalizes, or returns the value. Compared with siblings like github-repo-shape and jira-key-shape it implies a shape-checker, but the description itself does not name the action.

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, when-not-to-use, or named alternative among the many sibling *_shape/*-ok tools. 'value discarded' faintly hints this is a pure check rather than a lookup, but an agent gets no routing guidance.

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