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

With no annotations, the description carries the full burden of behavioral disclosure. It goes beyond the schema by stating the pay-per-call cost ($0.06 USDC on Base via x402) and the error behavior when a payment-signature header is missing (error data carries payment terms). This is valuable operational and error-handling context, though it doesn't mention other traits like rate limits or data retention.

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?

The description is three purposeful sentences: definition, usage/alternatives, and payment/error behavior. It is front-loaded with the core purpose, then alternates, then payment details. Every sentence earns its place with no filler or redundancy.

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 low-complexity tool with only two optional parameters and no output schema, the description adequately covers what the tool produces (a 30-day calendar with themes, post types, schedule), when to use it, and the critical payment/error behavior. Nothing essential for an agent to invoke it correctly is missing.

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%, so both parameters are already described in the input schema. The description adds a helpful example ('B2B invoicing tool, LinkedIn + newsletter, October') but does not materially expand on the schema's parameter semantics. The baseline of 3 is appropriate here.

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 states a specific verb ('Plan'), a concrete resource ('30-day content calendar'), and the deliverables ('daily themes, post types, and a posting schedule'). It also differentiates itself from related siblings by explicitly naming generate-marketing-strategy, generate-linkedin-post, and repurpose-long-form, so an agent can immediately tell what this tool does and does not do.

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 explicit: 'Use for planning a month of content.' It then names the exact conditions for alternatives: 'For the overall strategy behind it, use generate-marketing-strategy. For the posts themselves, use generate-linkedin-post or repurpose-long-form.' This gives clear when-to-use and when-to-use-something-else guidance with no ambiguity.

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