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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false), and the description adds genuinely non-obvious behavior: that instrument calls are discarded, bases/positions/quality are re-derived from peaks, the returned read may be a DIFFERENT LENGTH than the file, and that this operation does not itself modify the read. This is meaningful behavioral disclosure beyond structured data.

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?

Three tight sentences, front-loaded with the action, then the surprising behavioral note (different length), then the sibling relationship. Every sentence carries distinct information and none is redundant.

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?

For a non-trivial tool with an output schema (so return values needn't be explained), full annotation coverage, and 100% param documentation, the description supplies exactly the missing pieces: what it derives, the length caveat, and its relationship to the adopting sibling.

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 the schema already documents `table`, `_files`, `_subject`, and `document`. The description adds no parameter-level detail (e.g., how `table` affects scoring), 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+resource ('call the bases of a Sanger trace from the signal') and clarifies the mechanism (discarding instrument calls, deriving from peaks). It explicitly distinguishes itself from the sibling `adopt_trace_calls`, so an agent can tell the two apart without opening a schema.

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?

Names the alternative (`adopt_trace_calls`) and states the division of labor: this tool ANSWERS the question while the sibling applies the answer onto the read. Clear routing context, though it gives no explicit exclusions or when-not guidance (e.g., versus `call_mixed_bases_from_trace`).

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