list_search_covers

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows it's a safe, non-mutating operation. The description adds minimal value; it only restates the endpoint. There's no mention of response format, pagination, or any other behavioral traits, but given annotations cover safety, a 3 is reasonable.

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 extremely concise, consisting of a one-line summary and the endpoint URL. It's front-loaded with the main purpose. No wasted words, though it could be slightly more informative without sacrificing brevity.

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?

This is a simple tool with no parameters that reads data imaginably. The output schema exists, so return values are documented elsewhere. The description is minimally adequate, but lacks any detail on what 'search covers' represents or how it fits into the search feature. For such a simple tool, a 3 is fair.

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?

The tool has zero parameters, and the schema covers 100% (essentially empty). The description cannot add parameter meaning because there are none. According to the rules, with zero params, baseline is 4, and this is met since no additional info is needed.

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 'Get search covers' with a clear verb and resource, but it's very terse. It doesn't distinguish from sibling tools like list_search_authors, list_search_books, etc., which follow a similar pattern. Without context on what 'search covers' means (e.g., cover images for search results), its purpose is somewhat ambiguous.

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?

There is no guidance on when to use this tool vs. alternatives. The description includes only the endpoint URL, which gives a clue but doesn't explain use cases or exclusions. It's not misleading, but the tool's context among search-related siblings is omitted.

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