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

Annotations already declare readOnlyHint=true and idempotentHint=true, indicating the tool is safe and deterministic. The description adds that the tool produces variant calls in HGVS g. notation, which is consistent. However, it does not disclose details about alignment type (global/local), handling of reverse complement, or performance characteristics. The description does not contradict annotations, but it adds minimal behavioral context beyond what annotations provide.

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?

The description is a single sentence of 28 words that efficiently conveys the core functionality. It is front-loaded with the primary actions (align and call variants) and includes key output details (HGVS g. notation, optional coding effects). No extraneous information is present, and the structure is optimal for quick scanning.

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?

The description lacks important context such as the expected output format (list of variant objects vs. string), whether the alignment is global or local, and details about parameter interactions (e.g., frameStart only used when coding is true). No output schema is provided, so the description should compensate, but it does not fully address the return values or behavioral constraints. Given the tool's complexity (4 parameters, 2 required), the description is incomplete for effective agent use.

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 all parameters have descriptions in the input schema. The tool description adds only the context of 'HGVS g. notation' and 'coding effects,' which aligns with the 'coding' parameter. No additional parameter semantics are provided beyond the schema. According to the guidelines, baseline is 3 when coverage is high, and the description does not exceed that bar.

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 clearly states the tool's purpose: aligning a query to a reference and calling variants (substitutions, insertions, deletions) in HGVS g. notation, with optional coding effects. The verb 'align' and 'call variants' combined with the resource (query vs reference) and output format (HGVS g. notation) make the purpose unambiguous. This tool is distinct from sibling tools like 'pairwise_alignment' (which only aligns) and 'hgvs_convert' (which converts notation), as it generates variant calls.

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 does not provide explicit guidance on when to use this tool versus alternatives. Sibling tools such as 'pairwise_alignment' or 'variant_annotate' are not mentioned, and no conditions or exclusions are given. Users must infer from the purpose when to choose this tool, which is insufficient for effective agent decision-making.

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