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

Annotations already indicate a write operation (readOnlyHint=false) and non-destructive (destructiveHint=false). The description adds significant behavioral context: it is free ('FREE — no credits charged'), it auto-fills fields from the URL with override behavior, it deduplicates ('reuses an existing listing... rather than duplicating'), and it returns the product id. No contradiction with 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?

The description is concise (few sentences), front-loaded with the core purpose, and each sentence adds unique value. No redundancy. It efficiently covers purpose, usage, behavior, and parameters without wasted words.

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?

Given the tool's complexity (8 parameters, no output schema, but 100% schema coverage), the description covers all crucial aspects: what it does, when to use it, the auto-fill mechanism, dedup behavior, free nature, and return value (product id). It also warns about confirming with the user. No gaps remain for effective invocation.

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 8 parameters all described. The description goes beyond by stating that 'At minimum pass a url' and that 'the server auto-fills the name, tagline, description, logo, and X handle from the site; any field you pass explicitly overrides what's extracted.' This adds semantics about parameter relationships and defaults that are not in the schema, making it highly informative.

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 tool's action ('List a new product on ProductClank') and its key characteristic ('token-free listing'). It also distinguishes itself from the sibling tool 'search_products' by specifying the use case ('when search_products finds no existing match'). The verb 'list' combined with the resource and context makes the purpose explicit.

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 explicit guidance: 'Use this when search_products finds no existing match and the user wants to run a boost or campaign for a product that isn't listed yet.' It also instructs the agent to 'Confirm the product details with the user before calling,' giving a clear prerequisite. This effectively contrasts with siblings like 'boost_post' (which requires an existing product).

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