ensembl_sequence

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions the endpoints covered but fails to describe key behavioral traits: it doesn't specify if this is a read-only operation, potential rate limits, authentication needs, error handling, or what the output looks like (e.g., sequence data structure). For a tool with 5 parameters and no annotations, this leaves significant gaps in understanding how it behaves.

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 concise and front-loaded, stating the core purpose in the first sentence. The second sentence adds endpoint context without redundancy. Both sentences earn their place by clarifying scope, though it could be slightly more structured (e.g., bullet points for endpoints). No wasted words are present.

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?

Given the complexity (5 parameters, no annotations, no output schema), the description is incomplete. It lacks behavioral details (e.g., read-only status, error cases), output format explanations (beyond the 'format' parameter), and guidance on sibling tool differentiation. For a sequence retrieval tool with multiple parameters and no structured output schema, more context is needed to ensure the agent can use it effectively.

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%, meaning all parameters are well-documented in the schema itself. The description adds minimal value beyond the schema: it implies the tool handles both ID-based and region-based queries via the endpoints mentioned, but doesn't elaborate on parameter interactions or provide examples beyond what's in the schema. With high schema coverage, the baseline score of 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: 'Retrieve DNA, RNA, or protein sequences for genes, transcripts, regions.' It specifies the verb ('retrieve') and resources (sequences for various biological entities), making the function unambiguous. However, it doesn't explicitly differentiate from sibling tools like ensembl_lookup or ensembl_feature_overlap, which might also retrieve sequence-related data.

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 minimal usage guidance: it mentions covering '/sequence/id and /sequence/region endpoints,' which hints at two use cases (ID-based vs. region-based retrieval). However, it lacks explicit guidance on when to use this tool versus alternatives (e.g., ensembl_lookup for general feature info or ensembl_protein_features for protein-specific data). No exclusions or prerequisites are stated.

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