Coalescent Chart

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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so safety is covered. The description usefully adds things annotations cannot: the POST /v1/coalescent endpoint and the 50-credit Tier 3 cost, which matters for an agent budgeting calls. It says nothing about what the chart contains or how large the response is, but 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?

One front-loaded sentence defines the chart, followed by bracketed metadata for group, endpoint, required inputs and cost. Compact and scannable; the [Required] line is redundant with the schema but not costly.

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 a rich nested schema, full annotations and an output schema, the description only needs to convey purpose and routing. It conveys purpose adequately but leaves the comparison-family routing question (coalescent vs composite vs davison vs match_score) unanswered, which is the main gap given the sibling list.

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%: the nested input1/input2 birth-data objects carry detailed field-level documentation (timezone, timezoneOffset, houseSystem, ayanamsa). The description's '[Required: input1, input2]' merely restates the schema's required array, adding no semantic value, so the baseline 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 (Calculate) and resource (coalescent chart) plus a definition — 'the harmonic chart that resonates most strongly between two charts' — which tells an agent what output to expect. It does not, however, name or contrast with the nearby relational siblings (composite, davison, match_score), so differentiation must be inferred.

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?

No statement of when this tool should be chosen over astroway_relational_composite, astroway_relational_davison or astroway_relational_match_score, despite the crowded relational family. The [Group: Comparisons] tag and 'between two charts' imply the input shape but give no selection rule.

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