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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds one genuinely useful behavioral fact not in structured data: '真实算法引擎执行，非大模型生成', which tells the agent results are deterministic and computed rather than hallucinated. It omits what happens when both 'gene' and 'sequence' are supplied or neither is, and says nothing about output size or failure modes.

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?

Two compact clauses: trigger and return value, front-loaded under a bracketed label, with nothing padded or redundant. Slightly terse to the point of omitting needed constraints, but every sentence carries information.

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 2-parameter, no-output-schema tool the description is adequate: it names both inputs conceptually and states the return format. However, it leaves the gene-vs-sequence precedence rule unclear, which matters for a tool with zero required parameters, where an agent could easily call it with neither.

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 both parameters are already documented in the schema, and the description only echoes the same gene/sequence dichotomy. Baseline 3 applies since the schema does the heavy lifting and the description adds no format, mutual-exclusivity, or precedence rules.

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 (PCR primer design) and the trigger input (DNA sequence or gene), plus what is returned (candidate primer pairs with Tm/GC). It does not differentiate from the near-neighbor siblings act_primer_tm or act_sequence_*, so it falls short of a 5.

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?

'用户给了 DNA 序列或基因，要设计 PCR 引物' implies the usage context (user supplied a sequence or gene name and wants primers), but it never says when to prefer this over act_primer_tm (Tm-only) or when to skip it. No exclusions or alternatives are named.

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