list_facts

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

With no annotations, the description must carry the behavioral burden. It states the return is a list of fact summaries and includes parameter explanations, but it does not explicitly state that the operation is read-only, mention any side effects, or disclose limitations like pagination behavior or whether summaries omit certain fields. The phrase 'lightweight summaries' implies limited detail, which is helpful, but the absence of explicit safety or scope notes leaves some ambiguity.

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 compact and well-organized with a clear Args/Returns structure. Every sentence contributes to functionality. It is slightly terse — for instance, it could mention sorting or result ordering — but it remains efficient and easy to parse, achieving good conciseness without unnecessary fluff.

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 presence of an output schema (not shown here but indicated), the description need not elaborate on return structure, but it could offer more context around the tool's position among siblings. It explains the filtering parameters but omits any note on default ordering, whether results are sorted, or if there are any restrictions on combining filters. For a simple list tool with four parameters, the level of completeness is adequate but not exceptional.

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 description adds meaning beyond the input schema by explaining each parameter in the Args section: limit (with a range and default), subject_type, object_type, and predicate as filters. The schema only provides titles and types, so the description fills a critical gap, especially providing the limit constraint (1-100) not present in the schema. This is substantial added value.

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 'List facts as lightweight summaries.' It identifies the verb (list) and resource (facts) and adds the qualifier 'lightweight summaries' to indicate a summarized representation. This helps distinguish it from tools like query_facts or search_facts, but does not explicitly name alternatives or contrast levels of detail.

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 its many siblings (query_facts, search_facts, list_tags, etc.). It lacks any mention of alternatives, prerequisites, or scenarios where this tool is preferred. An agent is left to infer the appropriate context from the name and generic 'list' purpose.

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