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

With no annotations, the description carries the burden of behavioral disclosure. It reveals that each space includes a canCreateIssue field reflecting the caller's actual permission, which is valuable for decision-making. It does not mention pagination or other side effects, but for a listing tool this is acceptable given its simplicity.

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 sentences with no wasted words. The purpose is front-loaded, and the cross-tool references are placed strategically. Every clause adds value.

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?

For a parameterless list tool with no output schema, the description fully covers what it does, what it returns, and how it connects to sibling tools. No additional information is needed for an agent to correctly invoke it.

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 tool has zero parameters, so the baseline is 4. The description adds context about the return fields (space keys and canCreateIssue), which is helpful for understanding the output shape, though it does not need to explain parameters since there are none.

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 clearly states the tool lists spaces available to the caller and explicitly ties the output to the spaceKey filters of sibling tools (list_issues, list_statuses). This distinguishes it from other list_* tools by specifying the exact resource and its cross-tool utility.

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 implies usage context by noting that the spaces' keys are accepted by list_issues and list_statuses, and that canCreateIssue reflects the caller's permission. This gives an agent a clear reason to call the tool, though it does not explicitly state when NOT to use it.

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