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

No annotations are provided, so the description carries full responsibility for behavioral disclosure. It says 'Key discarded' but does not explain what the tool returns (e.g., boolean, error). More critically, the stated purpose (Jira key shape) does not align with the input schema, which has parameters like 'ref', 'url', 'city', etc., none of which appear to be a Jira key. This mismatch is confusing and fails to disclose how the parameters relate to the tool's function.

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 extremely short (two sentences), which is concise, but it lacks structure and essential information. It does not explain the parameters, the return value, or how to use the tool. It is under-specified rather than efficiently concise, and the brevity does not serve the agent's needs.

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?

With 9 parameters, no output schema, and no annotations, the description is grossly incomplete. It does not explain what the tool does with the parameters, what it returns, or how to use it. The mismatch between the description and the schema compounds the incompleteness, leaving the agent without sufficient context 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?

Schema description coverage is 100%, so each parameter is described. However, these descriptions (e.g., 'Git ref name; discarded after the shape check') are generic and do not connect to Jira key shape. The tool's description says it checks a Jira key, but no parameter is identified as that key. The parameter descriptions add little value beyond the schema and do not compensate for the lack of alignment with the tool's 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 verb and resource: 'Check a Jira issue key shape.' This clearly indicates the tool validates the format of a Jira issue key. However, it does not differentiate from sibling tools like 'domain-shape' or 'github-repo-shape' beyond the resource type, and it does not specify what constitutes a valid shape. The purpose is clear but not fully specific.

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 guidance is provided on when to use this tool versus alternatives. It does not mention that it is specifically for Jira keys, nor does it state any exclusions or conditions. Sibling tools include other shape checkers, so the agent would need to infer when to choose this one. There is no explicit usage direction.

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