Invalidate a fact

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

With no annotations, the description carries the full burden. It usefully discloses that the operation is journalled and history-preserving, but leaves key behavioral questions unanswered: what happens if no currently-valid fact exists, whether the close is idempotent, and what validUntil does retroactively or in the future.

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?

A single tight sentence plus a short tag; the disambiguating constraint ('without asserting a replacement') is front-loaded. Every clause earns its place.

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 a 3-parameter mutation tool with no annotations and no output schema, the description covers the core intent and the history-preservation trait but omits failure modes, validUntil semantics, and any return/confirmation behavior. Adequate but with visible gaps.

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 coverage is only 33%, so the description must compensate. It adds real value by framing subject/predicate as a slot identifier that selects the fact to close, but it adds nothing about validUntil beyond what the schema already says, leaving a third of the parameters undocumented in both places.

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?

Names a specific verb (close/invalidate) and the exact resource scope: the currently-valid fact in a (subject, predicate) slot. The clause 'without asserting a replacement' cleanly distinguishes it from lore_assert_fact, so an agent can route between the two without opening either 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?

Gives clear usage context by contrasting with the replace/assert case ('without asserting a replacement — e.g. "no longer true"'), which implicitly defines when this tool is the right choice. It stops short of naming lore_assert_fact explicitly or stating exclusions, so it is clear but not fully prescriptive.

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