pl_list_sources

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

Annotations declare readOnly, idempotent, and non-destructive hints, and the description adds valuable context: it explicitly states that the no-arg mode 'reads a local registry, spawns nothing' and that the source_id mode 'connects to that connector (lazy spawn on first use)'. It also discloses possible errors, adding transparency beyond the annotations.

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 dense and well-structured, using a first-sentence summary followed by mode-specific details and error notes. It is longer than necessary but every sentence provides useful information, making it efficient rather than verbose.

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?

The description covers both execution modes, optional filters, return values (catalog fields, live schemas), side effects (lazy spawn), and error cases. Given the tool's two-mode complexity and the presence of an output schema, this is a complete and self-sufficient description.

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?

Despite 0% schema description coverage, the description thoroughly explains both parameters: source_id triggers connector inspection, group filters by 'pl' or 'eu', and no arguments yields the full catalog. It even illustrates the native_params mapping with an example, fully compensating for the schema's lack of descriptions.

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 function: 'List available Polish/EU legal data sources, or inspect one source's live tool schemas.' It specifies both a verb and resource, and distinguishes it from sibling tools like pl_search and pl_get_document by focusing on discovery and schema inspection.

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 explains when to use each mode: 'Without arguments' for the full catalog, 'With source_id' for live schemas, and 'Optional group filter' for narrowing by 'pl' or 'eu'. It also notes the use case for native tools not covered by unified tools, but does not explicitly name alternative tools or when-not-to-use scenarios.

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