MCP Datastore Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions querying with optional features but fails to describe critical behaviors: whether this is a read-only operation (likely, but not stated), potential performance impacts (e.g., large queries), error conditions (e.g., invalid filters), or the return format (e.g., list of entities). This leaves significant gaps for an agent to understand how the tool behaves in practice.

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 a single, efficient sentence that front-loads the core action ('query entities from Datastore') and succinctly lists key capabilities ('optional filters, ordering, and pagination'). There is no wasted verbiage, and every word contributes to understanding the tool's scope.

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 tool's complexity (7 parameters, no annotations, no output schema), the description is inadequate. It doesn't explain what the tool returns (e.g., entity data structure), error handling, or usage constraints. For a query tool with rich filtering options, more context is needed to help an agent use it effectively without trial and error.

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 fully documents all 7 parameters with their types, descriptions, and constraints. The description adds minimal value beyond the schema by listing optional features (filters, ordering, pagination) but doesn't provide additional context like filter syntax examples or pagination limits. This meets the baseline for high schema coverage.

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 verb ('query') and resource ('entities from Datastore'), making the purpose unambiguous. It distinguishes itself from siblings like datastore_get (single entity retrieval) and datastore_listKinds (metadata listing) by emphasizing querying with filters, ordering, and pagination. However, it doesn't explicitly contrast with datastore_runAggregationQuery, which is a more specialized sibling.

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 no guidance on when to use this tool versus alternatives. It doesn't mention when to choose datastore_query over datastore_get (for single entities) or datastore_runAggregationQuery (for aggregated data), nor does it specify prerequisites like required permissions or data availability. Usage is implied by the tool name but not explicitly stated.

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