List primary tissues ranked by mutation burden.
Returns each tissue (COSMIC primary-tissue samples only, kept separate from cell
lines) with its total mutations, unique samples, and unique genes, most-mutated
first. Use for tissue-level questions; for cell lines use `search_cell_lines`.| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | Max tissues to return (1-100). Default 50. |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It describes the scope (COSMIC primary-tissue samples only), the output fields (total mutations, unique samples, unique genes), and the ordering (most-mutated first), which is helpful behavioral context.
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 sentences: the first states the primary purpose, the second provides details and alternative guidance. No redundant phrases.
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?
Despite lacking an output schema, the description clearly details the return value structure and context. With one well-documented parameter and simple behavior, the description is complete.
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?
The schema description for `limit` is 100% sufficient ('Max tissues to return (1-100). Default 50.'), so the tool description adds no additional parameter guidance, which is acceptable.
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 clear verb+resource+ranking: 'List primary tissues ranked by mutation burden.' Distinguishes from sibling tools by explicitly excluding cell lines and directing to `search_cell_lines`.
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?
Explicitly says 'Use for tissue-level questions; for cell lines use `search_cell_lines`,' which provides both when-to-use and an explicit alternative.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.