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

Adds real behavior beyond the annotations: idempotent adoption returning `already_present`, protection of existing renames and targets from being overwritten, and a possible `needs_confirmation` result. These are exactly the side-effect and repeat-safety traits an agent needs and that readOnlyHint/destructiveHint alone do not convey.

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?

Well front-loaded with the core action, then behavior, then guidance. Slightly chatty with the 'eight thoughtful ones beat forty' line, but it is short and each sentence carries information.

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 carries return-value explanation well (`already_present`, `needs_confirmation`), plus next-step and repeat-safety context. It omits the workspace parameter's meaning and the approval flow that `approvalId` implies, which is a modest gap for a 3-param write tool.

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 coverage is 67%, so the schema documents slugs (with maxItems 40) and workspace. The description clarifies that slugs come from the preset catalog and that metrics are tagged from it, but says nothing about the `workspace` or `approvalId` parameters, so it does not fully compensate for the 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: 'Creates the named presets as real metrics the workspace owns, tagged from the catalog.' An agent can distinguish this from ledger_metric_presets_list (read) and ledger_metrics_create (raw creation) 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?

Gives clear adoption guidance ('Adopt only what the user agreed to') and names the next step (ledger_feeds_create) plus the source list implied by the slugs. It does not explicitly contrast with the sibling ledger_metric_starters_adopt, leaving the presets-vs-starters choice to inference.

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