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

The description goes well beyond the annotations. While annotations only declare readOnly=false and destructive=false, the text warns 'SPENDS MONEY,' details the need for a paid plan/trial and write scope, stresses the idempotency-key requirement, and quantifies limits (credit balance, daily and monthly caps, once a day per product). This gives the agent crucial cost and failure-boundary information not present in structured data.

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 sentences with no wasted words. The 'SPENDS MONEY' warning is front-loaded, then the action, then prerequisites and constraints. Every clause conveys essential information, making it easy to scan and understand quickly.

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 single-parameter tool with no output schema, the description adequately covers the effect (top up Feed with moves), prerequisites (scope, plan/trial, idempotency-key), constraints (credit balance, caps, daily frequency), and cost implications. An agent has enough to decide when to call and what to expect. No critical gaps remain.

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 100% with idempotency_key fully described ('Client-minted key (1-200 chars). Reuse the same key on a retry.'). The description adds 'you mint' but does not introduce new semantics beyond restating the schema. Baseline 3 is appropriate since the schema carries the parameter meaning.

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 clearly states the action: 'run the growth-move generator on demand to top up the Feed with fresh marketing moves.' It specifies the resource (Feed) and distinguishes from read-only siblings like list_feed by emphasizing generation rather than listing. It also enumerates content areas (SEO, AI visibility, competitors, distribution), making the purpose unambiguous.

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 context: it's an on-demand top-up tool, requires a paid plan/trial and write scope, and is limited to once a day per product. It does not explicitly name alternatives or when-not-to-use scenarios, but the constraints and purpose make usage scenarios clear. No explicit exclusion of other siblings is stated, but the unique cost/limit warnings set it apart.

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