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

Annotations already declare readOnlyHint, openWorldHint, and destructiveHint, so safety is covered. The description adds useful behavioral detail about keyset paging and the next_cursor/start_cursor relationship that annotations cannot convey.

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-loads purpose, use case, endpoint, and paging behavior. Minor redundancy in restating the GET endpoint, but no wasted sentences.

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 output schema, the description adequately explains that it returns issue priorities, their ids, and one page with a continuation cursor. It could specify returned fields more, but is sufficient for a lookup tool.

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 coverage is 100%, so all five parameters are fully documented. The description's paging note largely restates what the start_cursor schema already says, adding no syntax or format detail beyond the structured data.

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 ('Lookup') and resource ('issue priorities and their ids') and adds a concrete purpose (needed to create an issue with a priority). It does not explicitly differentiate from the many sibling list_* tools, but the resource specificity makes selection unambiguous.

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 'needed to create an issue with a priority' gives a clear use context, telling the agent when this tool is the right lookup. It lacks explicit exclusions or named alternatives among the sibling list tools, keeping it from a 5.

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