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

Annotations already establish readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description does add genuinely useful behavioral context: the return payload includes not just the module but 'the rules the agent must follow,' which tells the agent the output is partly instructional. However, with no output schema, it omits how ambiguous or unmatched questions are handled and whether the response is a single module or several.

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, front-loaded with the core action and followed by the return contract. The long parenthetical topic list is dense but earns its space by helping the agent route a question. Slightly tighter phrasing could trim it without losing signal.

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 two-parameter, read-only lookup with no output schema, the description covers what the tool does and roughly what comes back (module plus rules). What remains thin is the routing/fallback behavior and any relation to the sibling retrieval tools, which an agent would need to pick confidently between them.

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%, with both parameters documented and the module enum fully enumerated in the schema, so the baseline is 3. The description's parenthetical topic list loosely echoes the enum values but adds no new meaning about how the module parameter interacts with auto-routing, nor about what a well-formed 'question' string should contain.

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 concrete verb-plus-resource ('Get the playbook module') and enumerates the covered question domains (plan, churn risk, renewals, meeting prep, stakeholders, portfolio health, situations, templates), so an agent can match a user question to this tool quickly. It stops short of distinguishing itself from the siblings get_module and list_modules, which is the main gap keeping it off 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?

Usage is implied by the topic list: use it when you have a key account management question. There is no explicit when-not guidance, no mention of when to prefer get_module or list_modules, and no statement about what happens if the question does not map to any module. The schema's 'Force a specific module instead of auto-routing' hints at an alternative path but the description never explains routing behavior or its fallbacks.

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