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

Beyond the readOnly annotations it discloses the auth requirement, the permission needed, and a real failure mode ('repository tokens are not accepted on /mcp'). It also explains the semantics of the computed sharedLane field and its three values plus sharedLaneDetail, which an agent cannot infer from annotations or schema.

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 core sentence is front-loaded and dense but each clause carries real information (fields, sharedLane semantics, auth). The trailing half drifts into explaining an alternate REST path with endpoint paths and preset payloads, which is useful but disproportionate for a one-parameter list tool.

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?

Covers auth, permission, returned fields, and derived-field semantics for a simple one-param read tool with a readOnly annotation and no output schema. It does not address result size or pagination behavior, though with a single owner filter and no paging parameters that is a minor gap.

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?

Only one parameter and schema coverage is 100%, with the schema already documenting 'Username, org slug, or 'platform''. The description restates that same enumeration but adds no syntax, format, or edge-case detail (e.g. case sensitivity, how 'platform' scopes results) beyond the schema, so the baseline 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 the CI runners registered to an owner') and enumerates exactly what comes back: id, name, url, labels, slots, online, last seen, revoked. It also defines the derived sharedLane value, which no sibling (revoke_runner, create_runner_registration_token, ci_health) provides, so an agent can distinguish it without opening a 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?

Gives concrete routing guidance for the read-only case: mint a repository token with {"runners": "read"} and use the REST endpoint instead, expanded with the ci-audit {"actions": "read"} preset. It also states the credential prerequisite (PAT with 'repo' scope plus rights to manage the owner's runners). What's missing is guidance on when to prefer this tool over adjacent siblings such as merjax_ci_health or merjax_ci_queue_status.

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