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

Beyond the annotations (destructiveHint=true, idempotentHint=true) it discloses the actual mechanism — a soft delete that flips status to `archived`, remains readable, and frees the name for reuse — which is exactly what an agent needs to reason about reversibility. It also adds a real access constraint not present in any structured field: 'Tier: sp500+ (sample rejected)'. The word 'Idempotent' merely restates idempotentHint, a small redundancy but not a contradiction.

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?

One compact sentence with the core action and the name-vs-id qualifier front-loaded, followed by consequences and tier. Nearly every clause earns its place; the lone waste is the terminal 'Idempotent.', which duplicates the annotation and could be folded in or dropped.

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 one-parameter mutation with an output schema already present, the description supplies everything an agent needs: what happens to the record, how to retrieve it afterward, how to reuse the name, and the tier gate. No meaningful gap remains.

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 100%, so the single parameter's case-insensitivity and 1–80 char bounds are already documented in the schema. The description's 'by its name (not id)' adds only a mild cross-sibling disambiguation and the 'frees the name for reuse' note, which is behavioral rather than parameter-level. Baseline 3 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 (soft-delete a watchlist) plus the key disambiguator 'by its name (not id)' and the resulting state change ('status flips to `archived`'). An agent can distinguish this from sibling delete_* tools and from save_watchlist/get_watchlist 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 operating context: it archives rather than removes, the record stays visible via list_watchlists status=all/archived, and the name becomes available for a subsequent save_watchlist — effectively routing the agent to the follow-up tools. It stops short of an explicit exclusion (e.g. when to use restore_deleted or undo_change instead), so it is clear but not fully discriminating.

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