Davison Chart

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

Annotations already declare readOnly, idempotent, non-destructive and non-openWorld, so the safety profile is covered. The description adds genuinely useful behavioral context in the cost line (50 credits, Tier 3) and the endpoint, but says nothing about output shape, latency, error conditions, or what happens with degenerate inputs (e.g. identical moments).

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 that defines the method, followed by a terse bracketed metadata block. Nothing is padded, though the [Group: Comparisons] line is largely redundant given the tool name prefix.

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?

An output schema exists, so return values need not be described, and the parameters are fully documented in the schema. What is missing for a tool sitting in a very crowded relational family is disambiguation from near-neighbours like composite and coalescent charts; without it an agent may pick the wrong relational technique.

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% and both nested chart objects carry extensive inline documentation (date/time formats, timezone vs timezoneOffset, houseSystem letters, coordinate ranges), so the schema does the heavy lifting. The description only names the two required params via the metadata tag and adds no semantics of its own, which is the correct baseline.

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 a Davison relationship chart") and explains the defining mechanism (midpoint in time and space between two birth moments), which is genuinely more informative than the bare name. It stops short of naming the sibling it differs from, and with relational_composite, relational_coalescent, relational_synastry and relational_match_score all present, that distinction is the one an agent most needs.

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 explicit when-to-use/when-not-to-use guidance and no named alternative. The method sentence (midpoint of two birth moments rather than, say, planet midpoints) implicitly lets an agent infer that this is not the composite chart, but that inference is left to the reader rather than stated.

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