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

With no annotations, the description carries the full burden. It discloses one behavioral trait: 'Key discarded' indicates the input is not retained. However, it does not state whether the tool is read-only, what it returns (e.g., a boolean, a normalized key, or an error), or any side effects. The mention of 'discarded' adds a small amount of transparency, but significant behavior remains undisclosed, so the score reflects partial coverage.

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 two short sentences, highly concise and front-loaded. It avoids unnecessary words and states the core function immediately. While it may be too sparse for full clarity, it is efficient in structure and length.

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 the tool has 9 optional parameters, no required fields, no output schema, and no annotations, the description is far from complete. It does not explain the expected return value, how the shape check is performed, or how to select among the many parameters. An agent would struggle to invoke this tool correctly without additional context. The description is inadequate for the tool's complexity.

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?

While schema descriptions cover all 9 parameters (100% coverage), the tool's description does not link the 'Jira issue key' concept to any specific parameter. The schema lists parameters like ref, url, city, and so on, none of which are obviously a 'key'. The agent cannot determine which parameter to supply for the shape check. The description fails to clarify this mapping, making parameter selection ambiguous despite the schema's per-parameter descriptions.

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 the shape of a Jira issue key. It is not a tautology and clearly indicates the tool's focus. However, it does not explicitly differentiate from sibling shape-checking tools (e.g., domain-shape, figma-url-shape), relying on the tool name for distinction. Overall, the purpose is clear enough for an agent to understand the basic function.

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 description provides no guidance on when to use this tool versus alternatives. It neither mentions conditions for use nor exclusions. Sibling tools like domain-shape or figma-url-shape exist, but the description gives no criteria for choosing this one. This leaves the agent to infer usage context from the name alone.

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