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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, but the description adds material facts the annotations cannot express: a PREMIUM license gate, and the error contract (never raises a protocol error, instead returns {"error": "..."} with remediation guidance, and is safe to retry after fixing input). That is exactly the kind of context an agent needs before committing to the call.

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 purpose, then coverage, then an inline example, then usage and error semantics. It is dense but every sentence carries a fact; the embedded JSON examples are compact enough not to bloat it.

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?

A single-optional-param generation tool with an output schema, full schema coverage, and annotations; the description additionally previews the return keys and the error path. An agent has everything needed to decide and call correctly.

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% and the single parameter is already well documented as an optional free-text fleet description, so the baseline is 3. The description adds value with a concrete input example ('20 agents, 3 with shell access, one finance bot') that shows the expected granularity and shape of that string.

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 artifact: 'Generate an audit-ready agent-governance policy for a fleet', and enumerates the six domains the policy covers. It is clearly separable from the sibling assessment tools it names.

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?

'Use when a fleet needs a written policy document' gives the positive trigger, and 'Not for assessing what the fleet currently does (inventory_report, audit_mcp_config)' gives an explicit exclusion plus the two alternatives to route to. Nothing is left to inference.

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