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

With no annotations provided, the description carries the full burden and does well: it discloses that results are 'numbered paragraphs with stable reference IDs', that filtering by ref is optional, and that 'English editions in v1'. These are behavioral details beyond the schema, though it doesn't describe error handling or the exact response structure.

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?

Three sentences deliver purpose, examples, scope, disambiguation, lookup guidance, and version note. Every sentence earns its place with no redundancy or filler. The structure front-loads the primary action and then adds supporting context.

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 straightforward get tool with no output schema and no annotations, the description covers the essential context: what it fetches, how results are formatted, how to filter, how to find book slugs, and what edition is available. It doesn't mention pagination or limits, but those are less critical for this tool type. Overall, it is adequately complete.

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 documents book, chapter, and ref adequately. The description adds a concrete example ('GEN-1:26') and clarifies that book slugs come from search_corpus, but it doesn't significantly expand on the schema's parameter documentation. Baseline 3 is appropriate.

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 the specific verb 'Fetch' and names the resource: 'a chapter of a digitized primary source text from the Wheel of Heaven library.' It provides concrete examples of source texts and stable reference IDs, and explicitly distinguishes itself from interpretation tools ('it returns the text itself, not interpretation'). This clearly differentiates it from siblings like get_interpretation.

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 gives clear guidance by labeling itself 'the primary-source tool' and contrasting with interpretation. It also tells users to find book slugs via search_corpus, which is a direct prerequisite. However, it doesn't explicitly mention when to avoid this tool in favor of get_source or compare_traditions, so while context is clear, explicit exclusions are absent.

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