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

No annotations are present, so the description carries the behavioral burden. 'Key discarded' discloses that the input key is not retained and hints at a side-effect-free read-style check, but it does not explain what the check returns, whether authorization is needed, or the semantics of the 'shape' validation.

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 short and front-loaded, but the phrase 'Key discarded' is a fragment that loses the subject and adds only minimal value. It is not bloated, but it is close to under-specification rather than genuinely concise clear communication.

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?

The tool has 9 optional parameters, no required parameters, no output schema, and no annotation support, yet the description does not explain which parameter carries the Jira key or what kind of result is produced. A string agent has too much ambiguity to invoke this tool confidently.

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 the baseline is 3. The description adds no mapping from 'key' to the nine schema properties and does not tell the agent which parameter should contain the Jira key, so it provides no extra parameter-level value.

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 has a clear verb-resource pair: 'Check a Jira issue key shape.' This makes the tool's basic goal understandable and distinguishes it from siblings like github-repo-shape or domain-shape, though it does not explicitly contrast with them.

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 phrase 'Check a Jira issue key shape' implies the use case: validating something as a Jira key. However, it gives no explicit conditions, exclusions, or alternatives to related shape-checking tools, so the agent has to infer when to pick this over a sibling tool.

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