Unpin Card

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

Annotations already declare this as a non-read-only, non-destructive operation. The description adds value beyond annotations by specifying exactly what state mutates (the user's pin list) and what remains untouched (the card and its board position), giving the agent a clear blast-radius picture. It doesn't cover idempotency or failure behavior, but the annotations lower the bar and the added scope detail is genuinely useful.

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?

Two sentences, zero filler. The core action and outcome are front-loaded in the first sentence, and the second sentence adds the critical scope boundary. Every word earns its place.

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 simple two-parameter tool with no nested objects and no output schema, the description plus rich schema documentation is nearly complete. The only minor gaps are idempotency (what happens if the card isn't pinned) and an explicit pointer to the inverse operation, neither of which is essential for correct invocation.

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?

The tool description adds no parameter information, but the schema description coverage is 100% — card_number is explained as distinct from card_id, and account_slug includes lookup guidance via fizzy_get_identity or fizzy_get_accounts. With the schema already carrying the full burden, baseline 3 is appropriate.

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 states a specific verb (unpin) and resource (card) with a precise outcome: removing it from the user's personal quick-access list. It also explicitly distinguishes this from card-level mutations by clarifying the card itself is unchanged, which differentiates it from siblings like fizzy_delete_card and fizzy_close_card.

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?

The description provides clear scope context: this affects only the authenticated user's pins and not the card itself, which implicitly tells the agent this is not the tool for board or card modification. However, it does not explicitly name alternatives (e.g., fizzy_unwatch_card for watch removal, or fizzy_pin_card as its inverse) or state exclusion conditions, so it falls short of a full 5.

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