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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds two genuinely useful operational facts — the GET endpoint and the 5-credit (Tier ½) cost — but says nothing about result size, pagination or how heavy a full catalogue response is, which matters for a browse-all endpoint.

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?

A single front-loaded sentence states the purpose, followed by compact bracketed metadata (group, endpoint, cost). Nothing is wasted or buried, though the metadata tags are structured fields that arguably belong outside the prose.

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?

With no required parameters and an output schema present, the description need not explain return values; it still states what the catalogue contains (patterns, short/full meanings, themes). It is sufficient for correct invocation, with sibling disambiguation the only real omission.

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 both parameters (fields, precision) are already documented in the schema, and neither is required. The description adds nothing about compact mode or precision, so the baseline 3 applies — the schema does all the work.

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 (the full angel number catalogue) and enumerates its scope: singles, masters, repeating, mirror and sequential patterns, plus short/full meanings and themes. 'Full catalogue' usefully contrasts with the single-number siblings (astroway_esoteric_angel_numbers_number, _decode, _today, _by_life_path_n), though it never names one of them explicitly.

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?

There is no explicit when-to-use or when-not-to-use statement. Usage is only implied by the word 'catalogue' — an agent can infer this is the browse-everything variant versus the per-number lookups, but the description never routes between the four angel-number siblings, which is the main selection risk here.

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