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

With no annotations, the description must disclose behavior itself. It only says the key is discarded, which is a useful no-retention hint, but it omits whether any network call is made, what a valid or invalid shape returns, or whether it validates existence vs. format. The schema mismatch further obscures 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?

Two short sentences with no filler; 'Key discarded' adds a behavioral fact without repeating the schema. The front-loaded purpose is immediately visible.

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 tool whose schema exposes unrelated parameters and no output schema or annotations, this description is far too thin. It fails to explain the expected key parameter, the return shape, or how to interpret the result, leaving an agent unable 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?

The schema provides detailed descriptions for ref, url, city, feed, host, json, and path, but none of these is a Jira issue key; the description never maps 'key' to any parameter. An agent cannot determine which property to fill, so the description adds no usable parameter meaning and the schema is actively misleading.

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 concrete action ('Check') on a specific resource ('a Jira issue key shape'), which distinguishes it from sibling shape-check tools for domains, GitHub repos, or files. It does not, however, mention that this is purely a format validation and not a lookup.

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 intended use is implied by the name and first sentence, but the description gives no when-to-use/when-not-to-use guidance and names no alternatives among the many sibling shape tools. An agent is left to infer that this tool is only for Jira key format checking.

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