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

Annotations already declare the write/idempotent/non-destructive profile, so the bar is lower. The description usefully adds that source text is untrusted reference material (a prompt-injection caution) and that idempotencyKey should be reused, which is behaviorally meaningful. It omits auth requirements, what happens on duplicate keys, or validation behavior.

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?

Three tight sentences with zero filler and the core action front-loaded. The idempotency note is brief and placed last. It is efficient, though the untrusted-material sentence could be folded in more tightly.

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, and annotations cover the safety profile. However, with 0% schema coverage the description leaves most parameters undescribed, which is a real gap for a 7-parameter write tool. Adequate at the core, incomplete around inputs.

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 0% across 7 parameters, so the description carries the full burden of explaining them, yet it only loosely gestures at sourceUrl, title, notes, and idempotencyKey. It leaves brandId, tags, and excerpt entirely unexplained and adds no format or constraint semantics. This is a substantial gap given the coverage.

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: saving a public source URL, title, and bounded notes as brand research evidence. This is clear and differentiates it from adjacent write tools like save_library_ad and save_brand_fact by naming the evidence type. It stops short of explicitly contrasting with those siblings, so it is clear but not fully disambiguating.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives despite a cluster of related siblings (add_intelligence_target, save_brand_fact, save_library_ad). The idempotencyKey reuse hint is operational, not a usage-routing rule. An agent must infer the trigger condition.

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