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

Annotations already declare not-read-only, idempotent, non-destructive, and closed-world, so the safety profile is carried structurally. The description adds one genuinely useful behavioral fact — 'Changes apply to later lookups' — confirming persistence across subsequent queries, but says nothing about partial-update semantics (omitted keys left unchanged) or what the response reports.

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 short sentences, front-loaded with the action and followed by the persistence note; nothing is redundant. The opening phrasing 'Turn collections of writings on or off' is slightly awkward but costs little.

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 rich annotations, full schema coverage, and an output schema, the description only needs to convey purpose, trigger, and persistence — all present. The remaining gaps (partial update behavior, relation to list_collections for discovering ids) are minor rather than blocking.

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 coverage is 100%, so baseline is 3; the description earns an extra point by mapping user-facing concepts ('traditions', 'collections of writings') onto the collections parameter, helping the agent decide which field to populate from a vague user request. It does not touch the bibles parameter beyond what the schema already documents.

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 and resource ('Turn collections of writings on or off for this account') and grounds it in concrete examples (church fathers, Catholic, Jewish sources). It reads as the write counterpart to get_account_settings without naming that sibling explicitly, which keeps it just short of a 5.

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?

Gives an explicit trigger ('when the user asks to include or leave out a tradition'), which tells the agent exactly the user intent that should route here. It does not state the inverse case (read settings via get_account_settings, discover ids via list_collections), so the exclusions are only implied.

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