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

With annotations already declaring destructiveHint=true and idempotentHint=true, the description adds real behavioral context: admin-only authorization, unknown key/id returning the known pipelines instead of erroring, existing stage keys staying stable, a stage with open deals being unremovable (reassign first), and the replace-all destruction rule where a stage sent without `requires` silently loses its requirements. This goes well beyond the annotations.

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 first sentence is densely front-loaded with operations, precedence, constraints, and error behavior. However, the 'When to use' sentence largely restates the operations already listed in that opening sentence, and the trailing example ('Don't let a deal reach Proposal until...') illustrates a gate without tying back to a specific parameter, so there is some 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?

Return values are covered by the output schema and the description's closing note. For a 6-parameter mutation tool it covers identification (key/id/default), all mutation targets, gates, authorization, idempotency implications, and failure behavior — nothing an agent needs to invoke it correctly is missing.

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 nested stage object (requires, requires_mode, role) is already fully documented in the schema, including the key/id precedence and the omit-both default behavior. The description largely restates these, so baseline 3 applies; it adds only light emphasis on precedence rather than new semantics.

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 gives a precise verb+resource (update a pipeline) and enumerates the mutations it supports: rename (label), re-point (applies_to), replace stages/entry requirements, and set default_for_types. It clearly separates itself from define_pipeline and archive_pipeline by scope, but it never names a sibling explicitly, so it stops short of a 5.

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?

There is an explicit 'When to use' clause scoping it to admins renaming pipelines, changing stages/gates, re-pointing, or setting defaults, plus the condition for editing the workspace default pipeline. No alternatives (define_pipeline, archive_pipeline, get_pipeline_summary) are named, and there are no negative exclusions, so it is clear context rather than full routing guidance.

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