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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds that it performs four coupled biophysical computations rather than a single lookup, which is useful framing, but since an output schema exists it does not need to restate results, and it says nothing about failure modes or missing-RBS behaviour.

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?

One front-loaded sentence with no filler; the colon-plus-list structure makes the four outputs scannable. It is dense but every clause carries content, with only minor cost from cramming four result types into a single sentence.

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 handling return values and annotations handling the safety profile, the description covers the essential question of what the tool computes and on what input. The only real gap is behaviour when the sequence lacks a usable RBS or start codon context.

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 mrna, _subject, _files and start_pos are all documented in the schema itself. The description's only param-relevant signal is the phrase "already in front of a start codon", which corroborates the 0-based start_pos semantics without adding anything the schema does not already state.

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?

A specific verb ("score") applied to a specific resource ("the ribosome-binding site already in front of a start codon"), and the description enumerates the exact quantities computed: Shine-Dalgarno hybridisation energy, competing mRNA folding, implied spacing, and relative initiation strength. This distinguishes it cleanly from the design-oriented sibling design_rbs.

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?

"Already in front of a start codon" implicitly signals that this evaluates an existing RBS rather than creating one, which is the main usage distinction an agent needs against design_rbs. However, no alternative is named and no preconditions are given (e.g. what happens if no plausible RBS is present upstream, or whether a CDS context is required).

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