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

With annotations only declaring the safety profile (not read-only, not destructive), the description supplies the real behavioral context: existing entities are extended rather than replaced, duplicates are skipped, entity names appearing in facts are auto-linked, and contradictory facts surface as possible_conflicts. That last point is valuable output-shape information absent from annotations. It stops short of stating permission or size-failure behavior beyond the 1000-character limit.

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 front-loaded paragraph that opens with the core action and then layers constraints and side effects. Every sentence carries a distinct constraint or behavior; only the scope sentence could arguably be folded in more tightly.

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?

For a 7-parameter mutation tool with no output schema, the description covers merge semantics, deduplication, conflict reporting, auto-linking, size limits, and scope meaning, which is most of what an agent needs. The absence of any mention of summary or entity_type semantics is the remaining gap.

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 57%, so the description needs to compensate for gaps and partly does: it constrains observations (one fact per item, under 1000 characters), explains keywords as search vocabulary because search has no semantic matching, and defines the 'global' value of scope. The name parameter's brevity is mentioned but summary and entity_type receive no description-level clarification.

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: create or update a knowledge-graph entity and add facts to it. The create-or-update semantics are spelled out (existing name extended, duplicates skipped), so the agent knows exactly what the call does. It does not differentiate itself from siblings like save_memory, correct_fact, or link, which keeps it from a 5.

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 operative guidance within the tool: one fact per item, keep names short, add keywords so search finds it later, and use scope 'global' for user facts that span projects. However, it never says when to pick this over save_memory, correct_fact, or link, so the alternative-selection gap remains.

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