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

The phrase 'Key discarded' discloses that the input key is not retained, which is a meaningful behavioral detail given the absence of annotations. However, the description does not state the result of the check, error behavior for invalid keys, or whether any network access or side effects occur.

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 with no filler; the first sentence front-loads the action and resource, and the second sentence adds a behavioral note. It is concise for a simple validation tool, though it sacrifices necessary detail.

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 no annotations, no output schema, and a schema whose parameters do not obviously include the Jira key, an eight-word description is insufficient. The tool definition omits the expected key format, the return value, and which parameter carries the key, leaving agents unable to invoke it correctly despite the clear overall purpose.

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 input schema contains seven described parameters, but none is identified as the Jira issue key; the closest candidate, 'ref', is described as a Git ref name. The description does not map 'key' to any schema property, so an agent cannot reliably determine which parameter to populate.

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 'Check a Jira issue key shape' identifies a specific verb and resource, and distinguishes this tool from sibling shape checkers like github-repo-shape or domain-shape. It is terse but not a pure tautology because it names the action and target object. It does not, however, define what a valid Jira issue key shape is.

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 explicit when-to-use or when-not-to-use guidance is provided. The description does not mention alternatives or situations where another sibling tool should be selected, so an agent must infer usage entirely from the tool name and general context.

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