estimate_birth_year

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

Annotations already declare this a safe read (readOnlyHint=true, openWorldHint=false), so the bar is low, and the description still adds real behavioral context: it produces a most likely year plus a save-ready explanation, and it cross-checks ages to flag probable namesake collisions (7 in 1850 vs 22 in 1882). It does not state how conflicts between relative-derived and age-derived estimates are resolved.

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-loaded with the core action, then the evidence heuristics, then the consistency-check behavior; only the parenthetical offset list is dense. Three sentences, each doing work, with no filler.

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 an output schema present, return-value detail is correctly omitted, and the description still covers the estimation heuristics and the cross-validation behavior for a 9-parameter tool. Gaps are minor: no note on required vs optional inputs, defaults, or precedence when relative-based and age-based estimates disagree.

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 coverage is 78%, so most parameters are documented in the schema itself; the description's value-add is explaining how those inputs combine (eldest child ≈ −27, spouse/siblings ±8, parents +18…+45, marriage ≈22) and that ages are also cross-checked. That is more than restating the schema, though the offsets largely duplicate the per-parameter descriptions.

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 names a specific verb+resource (estimate a birth year) and enumerates the evidence classes it consumes, so the agent knows exactly what kind of computation this tool performs. It does not, however, name or contrast itself with the close sibling birth_year_from_age, leaving the boundary between those two tools to 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?

Usage is implied rather than stated: the enumeration of relatives and record ages suggests 'use when you have collateral or documentary age evidence,' but there is no explicit when-to-use, when-not-to-use, or pointer to birth_year_from_age for the single-age case. Adequate but leaves routing to inference.

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