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

There are no annotations, so the description bears the full burden of behavioral disclosure. It only adds 'Key discarded,' which is vague and doesn't explain the output, error behavior, or how the shape check is performed. This is insufficient for an agent to predict the tool's behavior.

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 the core action is front-loaded in the first sentence. The second sentence, 'Key discarded,' is terse and earns its place only partially, but there is no fluff or redundant 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 no annotations, no output schema, and a seven-parameter schema with no obvious way to supply a 'Jira key,' the description is far from complete. It leaves crucial invocation details unresolved and provides no information about valid output or failure modes.

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 documents all seven parameters, so the baseline is 3, but the description adds no parameter-level context and even creates a mismatch by referring to a 'key' that is not present in the input schema. The agent cannot map the described purpose to any of the provided parameters.

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 a Jira issue key shape') and clearly identifies the resource as a Jira issue key, distinguishing it from sibling shape-checking tools. However, the meaning of 'Key discarded' is ambiguous and no input parameter named 'key' exists in the schema, which slightly undermines the 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?

The phrasing implies the tool should be used when one needs to check whether a value has the shape of a Jira issue key. It does not provide explicit when-to-use or when-not-to-use guidance, nor does it mention sibling alternatives like github-repo-shape or domain-shape.

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