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

Annotations already mark the tool as read-only, idempotent, and non-destructive, so the description doesn't need to restate that. It adds valuable context by explaining the computational method (date digits summed and reduced to a single digit, then tripled) and offering a link to the full output/error contract, which covers any missing edge-case details.

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 well-structured with clear sections (WORKFLOW, INPUT CONTRACT, DO NOT CONFUSE WITH) and is front-loaded with the primary purpose. It is slightly lengthy due to the distinctions and workflow notes, but every sentence serves a purpose, and the included docs link consolidates additional details.

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?

Given the tool's simplicity (no required params, read-only), the description is complete: it explains what it does, how it computed, when to use it vs. alternatives, and provides a docs link for errors/output. It doesn't explicitly mention response formats, but the schema already covers that, and the workflow note clarifies its standalone nature.

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?

The schema description covers the single optional parameter (response_format) with enum and default, achieving 100% coverage. The description adds context that no required parameters exist and that the date is automatically derived, but this relates to operational behavior rather than enhancing parameter understanding beyond the schema.

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 clearly states that the tool returns today's angel number computed from the current date, with a specific algorithm (sum and reduce digits). It explicitly distinguishes itself from sibling tools via the 'DO NOT CONFUSE WITH' section, naming asterwise_get_angel_number and asterwise_get_angel_number_personal and their purposes.

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 guidance is explicit: the 'WORKFLOW' section states it is standalone and suggests when to use the personal angel number tool afterward. The 'DO NOT CONFUSE WITH' section clarifies when to use alternative tools (specific number lookup vs. personalized from birth date), leaving no ambiguity about selection.

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