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

Annotations already mark readOnly=false, idempotent=true, destructive=false, so no contradiction; the description adds beyond them: admin-only auth, the guarantee that stages are untouched, and the side-effect warning that removing a stage moves every record standing in it. The confirmation protocol and prompt-injection warning further disclose operational constraints. This is rich behavioral context beyond the structured hints.

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 action, permission, and exclusions are front-loaded in the first two sentences, then the description moves into safety and data-handling guidance. It is longer than average but the length is mostly earned by a high-risk admin mutation and a required confirmation protocol; only 'This is a rare workspace-admin change' adds mild redundancy.

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 6-param mutation with no output schema and sparse schema descriptions, it supplies the critical operational context: admin permission, id source, what it does not touch, and a strict human-confirmation workflow. The remaining gaps (idempotencyKey semantics, workspaceId conditionality, return behavior) are non-trivial but secondary given the schema description on workspaceId and the idempotent hint.

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 only 17%, so the description carries the burden. It does explain id via get_pipeline_summary, name via 'Renames', isDefault via 'makes it the default for its type', and confirm conceptually via the explicit go-ahead requirement. However, it never explains the required idempotencyKey or when workspaceId is needed, so coverage is only partial.

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?

Opens with a specific two-part action ('Renames one pipeline, or makes it the default for its type'), naming the resource and the exact operations. It explicitly separates itself from stage-mutating siblings by stating 'It never touches the stages' and pointing to add_pipeline_stage and update_pipeline_stage. This is more than enough to distinguish it from the other pipeline tools.

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?

Cites the permission boundary ('Only a workspace admin may call it') and gives explicit alternatives for stage operations ('use add_pipeline_stage and update_pipeline_stage for those, and Anvil itself to remove one'). It also tells where ids come from (get_pipeline_summary) and instructs when confirmation is mandatory. This is explicit when/when-not guidance rather than implied.

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