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

Annotations already declare the tool read-only, idempotent, and non-destructive. The description adds meaningful domain context by clarifying the commercial consequence of the pricing_mode filter: fixed listings are buyable in one services_purchase call, while quote listings require a seller quote first. This goes beyond the safe-read profile and informs downstream tool selection.

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?

Two sentences with zero filler: the action and resource are front-loaded in the first sentence, and the second sentence clarifies the only non-obvious parameter semantics. The description is efficient and every clause earns its place.

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 paginated search tool with five parameters and no output schema, the description covers the core domain semantics: what is searched, the category space, and the practical meaning of pricing modes. It lacks explicit return-format or pagination-behavior details, but the cursor parameter and tool name make those inferable enough that this is a minor gap.

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?

With 100% schema description coverage, the baseline is 3, and the schema already documents all parameters. The description supplements this by naming the exact services_purchase call and the seller-quote requirement for pricing_mode, which is more concrete than the schema's phrasing. Category values are echoed from the enum, adding little new 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 opens with a specific verb-resource pair ('Search agent-to-agent service listings') and enumerates the exact service categories, making the tool's target clear. However, it does not explicitly name a sibling tool such as catalog_search_products or services_get_listing to differentiate from, so the agent must infer the market-search scope from context.

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 useful in-tool guidance by explaining that 'fixed' listings can be bought in one services_purchase call while 'quote' listings need a seller quote first. However, it never states when to choose this tool over alternatives such as services_get_listing, seller_list_listings, or services_list_open_requests, leaving the when-to-use decision implicit.

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