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

No annotations are provided, so the description carries the full burden of behavioral disclosure. 'Key discarded' only says the input is not persisted, and this adds little because each schema parameter already says it is discarded. The description does not reveal side effects, return values, permission requirements, or whether the check is local.

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 short and front-loaded, at the lower cost of front-loading the main purpose. But 'Key discarded' is almost redundant with the schema's per-field discarding notes, and the brevity leaves important context out, so this is under-specification rather than efficient conciseness.

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 simple validation tool, is no output, params, no return format, no indication of which param is the key, no mutual exclusivity rules, and no explanation of valid shape. The description alone is not enough to invoke the tool correctly.

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%, which gives a baseline of 3, but the description's 'Key discarded' does not map to any of the nine schema properties—none of which is a Jira key. Rather, than helping the agent understand which parameter to pass, the description actively conflicts with the input shape and makes correct invocation harder to infer.

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 first sentence states a specific action and resource: 'Check a Jira issue key shape,' which does distinguish it from sibling shape tools like domain-shape and github-repo-shape. However, the input schema contains no parameter named 'key,' so the stated resource is not directly addressable, weakening the purpose clarity.

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 guidance about when to use this tool over alternatives, no mention of conditions that favor it, and no exclusions. Sibling tools include similar 'shape' checkers, yet the description never tells an agent how to choose among them.

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