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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the description's main job is disclosing output semantics — it does say the signal is dropped and only bases/quality/bounds cross the boundary, which is genuinely useful framing. It does not cover failure modes (unreadable trace, unbounded trims) or that the trimming is a sliding-window mean-phred cut at the same base as the chromatogram panel (that detail lives only in the schema).

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 sentences, front-loaded with the operation and its input formats, with the pipeline framing immediately after. The closing metaphor ('a record crosses a wire as bases, and a peak cannot be written as one') is flavorful but does carry the real constraint that signal cannot round-trip, so it mostly earns its place.

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 values needn't be spelled out, and annotations cover the safety profile; the description supplies the conceptual boundary between trace and record that neither structured field conveys. Only the routing to sibling trace tools is missing.

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 carries trim, min_quality, reverse_complement, document and _subject semantics in detail. The description corroborates 'trim bounds' and 'per-base quality' but adds no syntax or defaults beyond what the schema states. 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 ('Read a Sanger trace (.ab1 / .scf / .ztr)') and pins the output shape: base calls as a record plus per-base quality and trim bounds. It also implicitly draws the line against signal-level siblings by declaring 'the trace SIGNAL stays here', though it never names trace_raw_signal or draw_trace to make the distinction explicit.

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 downstream rationale ('verify it against a reference, align it, gate on its quality') tells the agent what the output is for, which implies when to reach for it. But there is no explicit when-not and no named alternative (trace_raw_signal, trim_trace, call_bases_from_trace, draw_trace all sit adjacent), so selection still requires inference.

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