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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, covering the safety profile. The description adds genuinely useful meta-context the annotations do not: the credit cost (10 credits, Tier 1) and the POST endpoint. It says nothing about what the Balance number represents or how the result is shaped, but the output schema exists to cover that.

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?

One purpose sentence followed by compact bracketed metadata (group, endpoint, required fields, cost). Purpose is front-loaded, nothing is redundant, and the structured tags are scannable.

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 simple calculation tool with an output schema and full annotation coverage, the description supplies what the agent needs to invoke it: purpose, required inputs, endpoint and cost. The remaining gap is usage guidance against the many sibling numerology tools, which is scored separately.

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 50% (only fields and precision are documented in the schema; name and date are bare). The description implies name is a full name and restates the two required parameters, but adds no format or syntax detail beyond what the schema already encodes (e.g. the date pattern). Baseline 3 is appropriate given the partial coverage gap.

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 ('Calculate the Balance number') and disambiguates the system ('Numerology: Chaldean system'), which separates it from the Pythagorean, Kabbalistic and Vedic balance siblings. It also specifies the computation basis ('from initials of each part of the full name'), but it never names an alternative sibling to route against, so differentiation rests on the group tag rather than prose.

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?

The description states required parameters and cost but gives no when-to-use context and no exclusions or alternatives. Nothing tells an agent why it would pick Chaldean balance over, say, astroway_numerology_kabbalistic_balance or astroway_numks_balance, nor when a Balance reading is appropriate.

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