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 behavioral detail about the model's context window: it reads 1,000 bp and accepts 200–999 bp by padding. This is valuable beyond the annotations, though it doesn't elaborate on output behavior beyond what the schema would.

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 sentences plus a bullet, extremely concise and fully front-loaded with the core purpose. Every sentence adds information: the model identifier, input length range, and a critical model constraint (1000 bp window with padding for shorter inputs). No fluff.

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?

The description covers the essential behavior: the model's reading context and accepted input length. The output schema is present, so return values are understood. While it doesn't detail the 919 features or output format, the output schema presumably handles that. The input constraints are clear, and the tool's role among siblings is apparent. Slight gaps: no mention of typical use cases or performance notes, but it's sufficiently complete for an API.

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 coverage is 100% for all parameters (sequence, sequence_ref, sequence_name, model). The description adds minimal parameter-specific guidance; it only mentions the input length range (200–500,000 bp) which relates to the sequence parameter, but does not explain parameter usage beyond what the schema already provides. Baseline 3 is appropriate.

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 the tool's purpose: chromatin annotation across 919 features using a DeepSEA model. It specifies the input size range (200–500,000 bp) and distinguishes itself from sibling predictors like predict_enhancer and predict_promoter by focusing on chromatin state annotation.

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 description provides input constraints (sequence length range) and notes the model's context window, but it does not explicitly explain when to use this tool over alternatives. While the name and description imply chromatin annotation, there is no direct statement like 'use this for chromatin state prediction.' This is a clear purpose but lacks explicit selection criteria.

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