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

Annotations already declare readOnlyHint=true and destructiveHint=false, covering safety. The description adds valuable behavioral context by disclosing the output structure (stances: ally, orthodoxy, mixed, leave-out; one-line summaries) and the exact filtering behavior (case-insensitive substring match across title/authors/tradition/blurb). No contradictions 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?

Two sentences with no wasted words. The first sentence front-loads the tool's core purpose and output, and the second explains the single optional parameter. Every sentence 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?

Given the read-only annotations, a fully described query parameter, and the existence of an output schema, the description covers everything an agent needs to call the tool correctly. It names the stance categories and filter fields, leaving no actionable gaps.

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%, so the schema already fully documents the query parameter. The description repeats the case-insensitive substring filter nearly verbatim and adds only the word 'Optional,' providing no additional semantic depth beyond the schema.

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 uses a specific verb ('List') with a clear resource ('the performance-science reading corpus behind Performix') and details the output contents (book/cluster profiles, stance categories, and one-line summaries). It is clearly distinct from sibling tools that fetch a single book or list guides.

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 implies usage when an agent needs an overview of the book corpus, and the optional query filter indicates a filtering use case. However, it does not explicitly contrast with sibling tools like get_book or list_guides, so the when-not/alternatives guidance is left to inference.

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