get_data_registry_source_count

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

Annotations already declare readOnlyHint/idempotentHint/destructiveHint=false, so safety is covered; the description still adds the non-obvious 'null slots included' behavior, which meaningfully affects the returned number, plus an explicit return shape. It doesn't cover failure modes such as invalid registry_path, which keeps it short of a 5.

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?

Front-loaded with the count semantics, then the alternative routing, then the return shape — no wasted sentences. 'Read-only' mildly duplicates the readOnlyHint annotation, a small redundancy that keeps it from a 5.

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?

There is no output schema, and the description supplies the return contract ({ registry_path, source_count }) itself. For a one-parameter, read-only counter that is everything an agent needs before invoking it.

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% and the single parameter documents its own format with an example path, so the schema carries the load. The description adds only the framing that the path targets a UDataRegistry asset, which is the expected baseline-3 level when the schema is self-sufficient.

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 verb and resource ('Count the entries of DataSources[] on a UDataRegistry asset') and pins down the exact semantics ('null slots included'), which is the detail that distinguishes a raw count from a filtered one. It also names the sibling tools that serve the adjacent need, so an agent can route without opening a schema.

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 routes related intent to alternatives: 'For the sources themselves (class, source table) use list_data_registry_sources or get_data_registry_info.' It doesn't state a when-not condition for this tool itself (e.g. registry not loaded), but the routing guidance is clear enough to select correctly.

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