Citable — Google rank check

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

Annotations already declare readOnlyHint/openWorldHint, so the bar is lower, yet the description adds rich extras: the $0.012 USDC per-call cost, 'not charged if the feed is unavailable' failure behavior, and the 1-based position null-if-outside-window edge case. This meaningfully extends beyond the annotations.

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 dense sentences with zero filler. The most operationally critical fact (it is paid) is front-loaded, followed by the core function and return shape, then the no-charge condition. Every sentence 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?

With no output schema, the description properly carries the return-value burden: it states the position semantics, the URL/title, and the top-10 list. It could add the structure of the top-10 items or error behavior when the domain is absent entirely, but for a moderate-complexity tool this is nearly complete.

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%, so the schema fully documents all 5 parameters. The description adds only a light tie-in ('checked window' ↔ num), but per baseline rules a high-coverage schema carries the burden. No param detail beyond the schema is needed or provided.

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-resource pair: 'Google organic position of a domain for a keyword via a licensed SERP feed'. The description distinguishes it from siblings like citable_serp (which presumably returns raw SERP) and citable_keyword_metrics (keyword-level data) by making clear it resolves a single domain's position for a single keyword.

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 use case is implied — check where a domain ranks for a keyword — and the pricing note adds a practical caution. However, with 18 siblings present, the description never names alternatives or states when-not-to-use (e.g., no routing away from citable_serp or citable_domain_keywords).

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