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. Beyond that, the description explains the distinct behavioral character of each engine (e.g., exact k-mer is blind to diverged repeats, matrix scoring grades substitutions), which adds meaningful context about what the computation actually reveals.

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 two tightly written sentences with no filler. It front-loads the purpose and then gives the engine breakdown, making it easy for an agent to parse before drilling into the schema.

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 tool with 18 optional parameters, nested objects, and an output schema, the description supplies a clear high-level framing and enough engine context to orient an agent. It does not need to explain return values because an output schema exists, though it could be slightly more explicit about when to prefer each engine.

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 itself already documents all 18 parameters in detail. The description does not add syntax, format, or default guidance beyond what the schema provides; it only repeats the engine choice at a high level. A baseline 3 is appropriate when structured fields carry the parameter burden.

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 that the tool produces a dot plot for self-similarity or pairwise comparison and names the biological features it reveals (repeats, inversions, shared regions). It is a specific purpose for a visualization tool, but it does not explicitly distinguish itself from the sibling dot_plot_grid or other plotting tools.

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 opening phrase establishes the use case (self-similarity or pairwise comparison) and the description notes that the three engines answer different questions, which implies engine choice. However, it does not explicitly say when to choose this tool over sibling alternatives such as dot_plot_grid, and it provides no exclusions or preconditions.

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