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

With no annotations, the description carries the behavioral burden. 'Key discarded' is a meaningful privacy/disposal disclosure, and 'Check ... shape' implies a non-mutating validation, but the description does not state return values, side effects, or scope of the validation.

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 two sentences are short and front-loaded with the core purpose; there is no filler. However, the extreme brevity is not entirely appropriate for a tool with nine optional parameters and no output schema.

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?

The tool has no annotations, no output schema, and nine loosely related optional parameters, yet the description omits the Jira key format, the return value, and which parameter is relevant. This leaves a substantial gap for an agent trying to invoke it 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?

Although schema coverage is 100%, the description introduces a 'key' that does not exist in the schema's parameters. It gives no clue which of ref, url, json, path, etc. should carry the Jira key, so the description actively misleads rather than clarifying parameter use.

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 identifies a specific verb ('Check') and resource ('Jira issue key shape'), which distinguishes it from sibling shape validators like domain-shape or github-repo-shape. However, it never maps the key onto any of the nine schema properties, so an agent cannot tell which parameter to use.

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 when-to-use or when-not-to-use guidance is provided. With many shape-related siblings (domain-shape, figma-url-shape, wiki-title-ok), the description leaves the choice entirely to inference.

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