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

Beyond the annotations (readOnly=false, idempotent=false, destructive=false), the description discloses the 422 validation_error path for non-public or off-site URLs, the null-clearing semantics (label clears with it), the 60-char cap, the analytics side effect, and the required publish_items scope. This is unusually rich for a mutation tool and gives the agent the failure and side-effect profile.

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?

Purpose is front-loaded in the first clause, followed by constraints in priority order (URL rules, clearing, label, analytics, scope). Every sentence contributes actionable information with no restatement of the tool name or 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?

For a 4-param mutation tool with no output schema, the description covers validation, clearing behavior, side effects and authorization scope. It does not mention what happens to other item settings or the response shape, but the safety annotations plus this content leave little an agent needs to call it correctly.

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 only 50%, and the description compensates for exactly the undocumented parameters: product_url gets URL constraints (public https, own site, not pixeloa.ai/private network, nullable to clear) and product_cta_label gets its 60-char limit and override behavior. It adds real meaning the schema lacks.

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 names a specific verb and resource ('Update the item's public-page settings') and narrows scope to the 'product CTA link', so an agent can distinguish it from mutation siblings like publishItem or unpublishItem. It stops short of naming those siblings explicitly, which is the only thing keeping it from 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 context is implied rather than stated: it explains that the tool sets the 'view product' button on the public AR page and embeds, which tells the agent when the tool is relevant. It never names an alternative tool or an explicit when-not condition, so routing guidance is left to inference.

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