update_fact

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

With no annotations, the description carries the behavioral disclosure burden. It explains null-vs-empty-string semantics for context, valid_from, and valid_to, and notes the immutability constraints. It does not cover failure behavior (e.g., missing fact_id) or confidence null semantics, but the provided context is strong.

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 well-organized with a clear one-line purpose, a useful immutability note, structured Args, and Returns. Every sentence adds value and there is no redundancy or filler.

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 five parameters and no output schema, the description covers the purpose, all parameters, return type, and key behavioral nuances. Missing details include confidence null handling and error cases, but the tool remains safely invocable as documented.

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 0%, so the description must fully explain parameters. It does so well for fact_id, context, valid_from, and valid_to, including null/empty behavior. Confidence gets a range note but lacks the equivalent null-means-unchanged clarification, leaving a minor gap.

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 operation: "Update an existing fact's metadata." It specifies the resource (facts) and the scope (metadata only), and the immutability note distinguishes it from add_fact and delete_fact siblings.

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 explicitly tells the agent that subject, predicate, and object cannot be changed and that those require delete and recreate. This gives clear when-to-use and when-not-to-use guidance relative to sibling tools.

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