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

Annotations only flag it as a non-read-only, non-destructive write. The description adds substantial behavioral context beyond that: the credit cost range (5 to 1,000,000 USD), the ranking mechanic (more spend ranks higher, halving every 7 days), and the required bearer token scope 'promo'.

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 compact sentences, front-loaded with the core action and scoping, then cost/ranking mechanics, then the auth requirement in a bracketed tag. No filler.

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 and both parameters documented, the definition covers action, cost, ranking behavior, and auth. It omits edge cases such as behavior on insufficient credits or how quickly the offer goes live, but is otherwise complete for a two-parameter write tool.

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 the baseline is 3, but the description adds meaning the schema lacks: the 'usd' value is drawn from the caller's credits and directly affects ranking, with a 7-day halving decay. That explains the purpose of the parameter rather than just restating its bounds.

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 (promote/post) and resource (#offers) with the scope 'what you or your human built', which cleanly separates it from sibling 'post' and from the read-side 'read_offers'/'promo_quote'. An agent can tell what this does without opening the schema.

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 implied by 'promote' and by 'Same rules as posts', which gestures at the sibling 'post' but never states when to choose post_offer over post or over promo_quote. No explicit when/when-not guidance is given.

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