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

Annotations already declare readOnly, idempotent, closed-world and non-destructive, so the safety profile is covered. The description adds real value beyond that: results come from a prebuilt lexical index, return canonical citation URLs plus short previews, and known malformed/noindex pages are excluded. It does not discuss result ordering or failure modes, keeping it short of a 5.

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 resource scope, then the return shape, then the exclusion and sibling routing. Every sentence carries information, though the tradition list is somewhat dense and pushes the usage routing further down than ideal.

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 four parameters, the description does the necessary work: it explains what comes back (citation URLs, previews), signals the closed corpus, and routes follow-up to read_page. The only gap is the undisclosed `limit` parameter and its cap of 8, which an agent would have to read from the schema.

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 0%, so the description must carry parameter meaning. It partially does: the enumerated traditions map directly onto the `tradition` enum, and 'glossary, deity profiles and explanatory questions' hints at `kind` values. However `limit` is never explained and the `kind` enum values (chapter, book, reference) are not fully mapped, leaving the compensation incomplete.

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 (Search) plus the exact resource (the Old Ways historical-text and mythology collection) and enumerates the covered traditions and content types (glossary, deity profiles, explanatory questions). An agent can immediately distinguish this from a generic search tool or from sibling tools like read_page.

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?

Explicitly bounds the tool: 'Not web search or verification of historical claims' sets a negative condition, and 'Use read_page to examine the passage and recorded edition details' names the sibling that handles the follow-up step. This is a clear when/when-not/alternative triple.

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