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

Annotations cover the safety profile (not read-only, not destructive, not idempotent), so the bar is lower; the description still adds real context beyond them: the return payload (board plus new frame), that it costs no credits, and the concrete auth path (OAuth or an Authorization: Bearer acd_live_… header with a settings URL). It does not explain what happens if the revision is stale, but that is a minor omission.

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-loaded with the action, then returns and cost, then auth. Three compact sentences with no filler; the auth sentence is long but earns its place as a hard prerequisite.

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?

An output schema exists so return values need not be explained, yet the description still names the return payload. Combined with cost and auth details, an agent has what it needs; only the non-idempotent/concurrent-revision behavior is left unaddressed.

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%, including the revision parameter's optional read-then-write behavior, so the schema carries parameter semantics. The description adds only a loose paraphrase ('chosen cards', 'labelled frame') and no format or constraint detail, matching the baseline 3.

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: 'Wrap chosen cards in a labelled frame that encloses them.' An agent can distinguish this from add_frame (which creates a frame without wrapping existing cards) and arrange_cards. It does not explicitly name those siblings, so it falls 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?

Usage is implied by 'chosen cards' plus the required ids/label/canvas_id parameters, but there is no explicit statement of when to use this versus add_frame or arrange_cards, and no exclusions or prerequisites beyond the auth note. Adequate but clearly gapped.

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