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

Annotations already declare readOnly/idempotent/non-destructive and closed-world, so the safety profile is covered. The description adds real value beyond that: sort order by newest activity, that a total is returned for paging, that archived missions are filtered out, and the required missions:read scope.

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?

Three tightly packed sentences, front-loaded with the resource and scope before exclusions and auth. The enumeration of returned fields is somewhat long but earns its place since there is no output schema.

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 usefully enumerates key returned fields (issueId, title, activity, pipelineProgress, review/check/test state, PR, cost, paused), and it covers ordering, exclusions, paging total and required scope. Only the precise pagination mechanics are left vague.

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 the schema already explains limit, offset, search, activity and projectId in detail. The description only alludes to paging ('total for paging') and filters, adding little beyond the schema, so the baseline 3 applies.

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?

States a specific verb and resource ('List missions'), the scope ('caller's accessible projects'), the ordering ('newest activity first'), and paging behavior ('with total for paging'). This clearly distinguishes it from get_mission and inspect_mission without opening any schema.

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 notes the exclusion of archived missions and the required missions:read scope, plus the schema tells the caller to narrow with projectId/activity/search before raising limit. However, it never states when to prefer this over get_mission or inspect_mission, so selection guidance is only implied.

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