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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered without the description. The description's only added behavioral signal is the cost note (plan-dependent, not in the public credit manifest), which is genuinely useful but thin. No return-shape detail is needed since an output schema exists.

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 compact sentences with the core purpose front-loaded, followed by clearly demarcated metadata lines for group and cost. Efficient, with no redundancy in the prose itself.

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 low-complexity single-lookup endpoint with one required parameter, full schema coverage, an output schema, and read-only/idempotent annotations, the definition supplies enough to invoke correctly. The missing piece is routing guidance among the crowded angel-number sibling set, which is a usage gap rather than a completeness failure.

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 all three parameters (n, fields, precision) are already documented in the schema. The description restates the life-path domain from the schema and adds nothing about `fields` or `precision` (compact-mode round-tripping), so this is the baseline 3.

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 resource (angel numbers) and the axis that selects it (aligned to a given life-path number), and repeats the valid input domain. It is distinguishable from siblings by that parameter axis, though it never names an adjacent tool like angel_numbers_number or angel_numbers_today to sharpen the distinction.

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?

"Useful to identify recurring numerical signatures aligned with one's soul path" is a benefit statement rather than when-to-use guidance. No conditions, exclusions, or alternative tools are named, so the agent must infer when this beats the other four angel-number endpoints.

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