List Project Runners

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint, so the safety profile is covered. The description adds one genuinely useful behavioral fact—that results include group and instance runners, not just project-scoped ones—which affects result interpretation. However, it says nothing about result volume, default page size, or whether paging is needed, despite page/per_page parameters existing.

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 short sentences, each earning its place: scope first, supported filters second, sibling routing last. Nothing is repeated from the schema or annotations, and the most decision-relevant information is front-loaded.

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 read-only list tool with no output schema and annotations covering safety, the definition covers purpose, scope, filters, and the main alternative. The remaining shortfall is pagination and project_id handling, which an agent would have to infer from the schema alone, but this is a modest gap rather than a blocking one.

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 0%, so the description must carry the load, and it names only four of seven parameters (type, status, paused, tag_list) as filters without explaining semantics beyond their names. The two enums are self-documenting in the schema, but page, per_page, and project_id receive no mention at all in the description, leaving a meaningful compensation gap.

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 runners') plus the scope that matters most: 'a project can use, including group and instance runners.' It also names the sibling it is not (gitlab_get_runner), so an agent can distinguish the two without opening either 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 final sentence explicitly routes the agent to gitlab_get_runner when it needs tags or settings for a single runner, which is the key disambiguation. It stops short of stating when not to use this tool (e.g., to find runners across all projects or at group scope) and gives no guidance on pagination-driven repeated calls.

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