Build a probabilistic Bloom filter from string items and test query strings for membership, ensuring no false negatives.
Build a Bloom filter from items and test membership of query items (probabilistic, no false negatives).
| Name | Required | Description | Default |
|---|---|---|---|
| items | Yes | Strings to insert into the filter | |
| query | Yes | Strings to check for membership | |
| fp_rate | No | Target false positive rate (default 0.01) |
Changes observed during successful MCP inspections.
v0.1.11Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It discloses the critical probabilistic behavior and the no-false-negatives guarantee, which is meaningful beyond the tool name, though it does not describe the return shape or false-positive behavior explicitly.
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?
A single front-loaded sentence with zero waste. It includes the essential caveat (probabilistic, no false negatives) without padding.
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 pure algorithm tool with full schema coverage and no annotations, the description is nearly complete. It omits return-value details, but 'test membership' implies boolean-like results and no output schema is provided.
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%, so all three parameters are documented in the schema. The description references items and query but adds no syntax, format, or fp_rate semantics beyond what the schema already provides, making 3 the baseline.
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 two-part operation: build a Bloom filter from items and test membership of query items. The parenthetical clarifies the probabilistic nature and the no-false-negatives guarantee, so the agent can distinguish this from exact set or hash operations.
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 implies usage through its stated purpose but gives no explicit when-to-use guidance or alternatives. There are no obvious sibling tools for Bloom filtering, so this is adequate but not rich.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.