get_ydna

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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false). The description adds genuinely useful behavioral context: the has_data flag is false when no Y-DNA is recorded, which the text flags as the normal case — sparing the agent from treating an empty result as an error.

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?

Front-loads the purpose, then layers scoping and interpretation. The domain exposition is slightly long for a lookup tool, but each sentence carries meaning and the has_data caveat is placed usefully at the end.

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?

There is no output schema, and the description compensates by naming the has_data output signal and what a shared terminal clade means. For a read-only two-parameter lookup this is close to complete, with only the include_raw return shape left implicit.

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 are fully documented by the schema itself. The description adds no syntax or format detail beyond that, 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 and resource — reports a person's Y-DNA haplogroup — and adds scope detail (broadest clade to terminal). It is clearly distinct from the DNA-matching siblings (get_dna_matches, parse_dna_segments) by domain, though it does not name any sibling 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?

Provides interpretive context about what Y-DNA does and does not tell you (paternal line only, corroborates a surname rather than proving a named link), which implies when the result is meaningful. However, it never states when to choose this over the other DNA tools or what prerequisites exist — usage is implied rather than explicit.

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