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

Annotations only declare readOnly=false, destructive=false, openWorld=true; the description goes further by disclosing that each call is user-confirmed by default, that it reaches other people (an external, visible side effect beyond a generic openWorld flag), and that a credit balance precheck and scoped API key are required. It still does not say what happens on failure or whether an existing boost is replaced, so it is additive but not exhaustive.

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?

Front-loaded with the core action and a tight chain of operational notes; nothing is buried. It loses a point for redundancy, restating the product lists twice (once in sentence one, again in sentences three and four).

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 2-parameter mutating tool with annotations already covering the safety profile, the description covers auth, credits, confirmation, and one-per-call semantics. The main omissions are post-call behavior (what the response contains and how to verify the boost applied) and failure/insufficient-credit handling.

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% and both parameters are documented in the schema, so the baseline is 3. The description confirms the product-to-marketplace mapping (Bayut: signature/hot/property_of_the_week; dubizzle: refresh/featured), which is useful given the malformed enum values, but largely repeats the schema text rather than adding new meaning such as cost, availability, or duration per product.

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 ('Apply') and resource ('a Bayut boost ... to a listing') and enumerates the concrete products on each marketplace, so an agent knows exactly what action results. It also scopes the operation to one product on one listing, which is unambiguous even among the large Bayut/zoopla/property-finder sibling set.

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?

Gives clear preconditions: check get_credits first, and the account needs a Cotlet API key with access to this app. It also explains the default confirmation flow and how to switch it off. It does not name a sibling alternative or state when a boost should be skipped in favor of another tool, so it stops short of full when/when-not routing.

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