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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only says 'Key discarded,' which hints that input is not retained, but it omits the return value, validation result semantics, error behavior, and whether any network or external lookup occurs. 'Check' implies a read-only operation, but that is not made explicit.

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 very short and front-loaded, with no filler. 'Check a Jira issue key shape' is an efficient statement of purpose, and 'Key discarded' is a terse behavioral note. However, the extreme brevity borders on under-specification, which prevents a perfect score.

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 validation tool with no output schema and no annotations, the description should explain at least what input represents the key, what shape is expected, and what the caller receives. None of that is provided. The description is only a name expansion, not enough for an agent 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?

The schema has seven parameters with individual descriptions, but none of them is named 'key' or explicitly mapped to the Jira key being checked. The description adds no meaning to the parameters and leaves the agent guessing which field (ref? url?) actually contains the key. High schema coverage does not help when the central parameter is not identified.

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: 'Check a Jira issue key shape.' This makes the core function clear and distinguishes it from sibling shape-checkers such as github-repo-shape or domain-shape. However, it does not define what constitutes a valid Jira key shape, so exact behavior is left implicit.

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 versus the many sibling shape-check tools, nor any mention of prerequisites or expected input context. The purpose is inferable from the name and first sentence, but the description does not actively route the agent to the correct choice.

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