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

Annotations are absent, so the description carries the full burden of behavioral disclosure. It only states 'Key discarded,' which hints at a side-effect-free validation, but does not clarify that the tool accepts a wide variety of unrelated inputs and discards them all, nor does it disclose the return format or any side effects for the other parameters.

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 concise—two short sentences—and front-loads the primary action. However, the brevity sacrifices necessary detail, making it under-specified rather than appropriately concise. It earns a mid-score for being terse but fails to deliver substantive content.

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 severely incomplete. It does not explain what a valid Jira key shape is, how to invoke the tool with the given parameters, or what the result looks like. The description's focus on 'key' conflicts with the schema's generic fields, leaving the agent without sufficient context to use 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%, and each parameter already has a descriptive explanation (e.g., 'Git ref name; discarded after the shape check'). The tool description adds no additional parameter context beyond the schema. Per the rubric, a baseline of 3 is appropriate when the schema is fully documented.

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'), but the input schema contains nine parameters (ref, url, city, feed, host, json, path, zone, query) with none explicitly labeled as a Jira key. This mismatch makes the purpose ambiguous and fails to distinguish the tool from sibling shape-checkers like domain-shape or github-repo-shape.

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. There is no mention of conditions, exclusions, or sibling tools. The description only repeats the core action without contextual cues for an agent to decide between this and similar shape validators.

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