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

With no annotations, the description carries the behavioral burden. It clearly discloses the mandatory payment ('Requires a machine payment (MPP over Stripe)') and the unpaid fallback ('returns the exact payment challenge and the URL to retry against'). It does not describe the full return format, but it covers the most important behavioral quirks.

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?

The description is short and front-loads the essential 'PAID' fact before the purpose. The standalone 'PAID.' is slightly redundant with 'Requires a machine payment...', but every other sentence contributes necessary information about behavior and failure mode.

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 single-optional-parameter tool with no annotations and no output schema, the description supplies the key behavioral context: paid operation, full or topic-filtered result, and unpaid response. It lacks explicit sibling routing, but that is already penalized under usage guidelines rather than completeness.

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 topic parameter is already described as 'Optional keyword filter.' The description's 'subset matching a topic' essentially restates the schema without adding formatting, syntax, or matching details, so the baseline of 3 applies.

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: 'Return the full Forward Deployed Engineering ruleset, or the subset matching a topic.' The 'full' and 'PAID' markers distinguish it from the sibling fde_lessons_preview, but no sibling is explicitly named.

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: use when you need the paid/full ruleset, optionally narrowed by topic. The payment prerequisite is clear, but the description does not explicitly say when to use fde_lessons_preview or other siblings, nor does it state exclusions or alternatives.

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