Open entities

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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuine context the annotations cannot: results include every relation touching the entities, a relation's far end may fall outside the result set, and nonexistent names are silently ignored rather than erroring. That last point is the most valuable behavioral disclosure.

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?

Three short sentences, purpose front-loaded, with the alternative-tool pointer and the relation-expansion caveat each earning their place. No 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?

For a one-parameter read tool with an output schema, the definition covers what it does, what comes back (including relations that reach outside the result), how missing names behave, and which sibling to use instead. Nothing needed to call it correctly is absent.

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 100%, so the single 'names' parameter is already documented, giving a baseline of 3. The description still adds meaning by stressing 'exact name' matching and the ignore-missing-names semantics, which the schema's 'Exact names of the entities to open' only hints at.

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 ('Open entities') and pins the matching mode to 'exact name', which immediately separates it from keyword-oriented siblings. An agent can tell it apart from search_nodes 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?

Explicitly routes the agent to the alternative: 'To find entities by keyword, see search_nodes,' giving the condition (exact vs keyword) that selects between them. No prerequisites or exclusions are left to inference beyond that.

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