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

With no annotations, the description must bear the full burden of behavioral transparency. It only says the key is discarded and the shape is checked. It does not disclose what happens on success or failure, whether any side effects occur, or what return value the agent should expect.

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 concise and front-loaded with the core action, but it is too terse for the complexity of the tool. The second sentence ('Key discarded.') adds minimal detail, and the overall brevity leaves out critical invocation and behavior information.

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?

Given 9 parameters, no required fields, no output schema, and no annotations, the description is far from complete. It does not specify which input to use, what return value to expect, how errors are handled, or how the tool fits into a larger workflow. An agent would be unable to reliably invoke this tool based solely on the description.

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?

Although all 9 parameters have schema descriptions (100% coverage), those descriptions are unrelated to a Jira issue key (e.g., 'Git ref name', 'IANA timezone name'). The tool description does not explain which parameter should hold the Jira key, so the schema and description fail to map inputs to the tool's actual purpose.

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 action ('Check') and a specific object ('Jira issue key shape'), which makes the tool's purpose clear and distinguishes it from sibling shape-checking tools like domain-shape or github-repo-shape. It loses one point because it does not explicitly name an alternative or clarify which input parameter should contain the Jira key.

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?

No usage guidance is provided. The description does not say when to use this tool versus other shape-checking tools, nor does it give context such as 'use to validate a Jira key before an API call.' The purpose is implied but not explicitly connected to any workflow.

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