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

Adds substantial behavior beyond the annotations (which only declare non-read-only, non-destructive, non-open-world). Discloses idempotent semantics (`already_present` on repeat), non-overwrite guarantee for renames and targets, empty starting state, and a possible `needs_confirmation` outcome — exactly the traits an agent needs to sequence the call correctly.

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?

Front-loads the operation, then idempotency/non-overwrite, then adoption discipline, then next step. Four compact sentences, each earning its place with no filler.

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 mutation semantics, idempotency, state after creation, and follow-on tools for a tool with no output schema. The only gap is that the `needs_confirmation`/approvalId flow and workspace-key interaction are not spelled out, though the schema covers the former.

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% and the schema documents slugs (source, min/max, maxItems 40) and workspace. The description implies a slug list ('named presets') but adds no new syntax or format guidance, and approvalId (linked to `needs_confirmation`) is left for the schema. Baseline 3 fits.

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 concrete verb (creates/adopt) and resource (named presets as real metrics the workspace owns, tagged from the catalog). Clearly distinguishes itself from ledger_metric_presets_list (catalog browsing) and ledger_metric_starters_adopt / ledger_metrics_create by describing catalog-sourced adoption into owned metrics.

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 explicit adoption guidance ('Adopt only what the user agreed to', anti-pattern warning about noise, 'eight thoughtful ones beat forty') and a next-step handoff to ledger_feeds_create or a first reading. Does not name when to prefer ledger_metric_starters_adopt or ledger_metrics_create instead, so full alternative routing is absent.

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