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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), and the description goes further by disclosing what is produced (health signals, per-reason interventions and email drafts) and how behavior branches when churn_reasons is omitted. It does not mention length, cost, or rate limits, so not a full 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?

Three sentences, front-loaded with the core deliverable, and no wasted preamble. The churn-reasons fallback is stated twice (once in the opening, once in the final sentence), which is mild redundancy.

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 10-parameter tool with no output schema, the description sufficiently sketches the return shape (health signals, interventions, per-reason email drafts, discovery-kit fallback). Combined with the 100%-covered schema, an agent has enough to call it correctly; only the volume/format of the output remains unspecified.

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 every parameter and the baseline is 3. The description adds cross-parameter behavior (business model drives health-signal weighting, sector notes come from your_sector/industry, current_interventions are compared against the playbook), which is useful but mostly echoes the schema text.

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 names a specific action (takes segment, business model, churn rate) and a concrete deliverable (retention playbook with health signals, interventions and email drafts per churn reason). It is unmistakably distinct from the sibling set (competitive_intel, crisis_planner, pmf_scorecard, etc.), none of which are retention-playbook tools.

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?

It gives explicit conditional guidance: 'If you do not know why customers leave, leave the churn reasons out and you get a churn discovery kit.' That is a clear when-to-use-which-mode rule. It does not name any alternative tool or state exclusions relative to siblings, which keeps it short of a 5.

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