Get entity

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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is covered. The description adds useful return context (reference images are bundled, built-in entities are included and flagged), which is genuine value beyond annotations, but it says nothing about error behavior for unknown ids or auth needs.

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?

Two short sentences, front-loaded with the core action and followed by scope notes. Nothing is wasted, though the second sentence is more about return shape than invocation.

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?

With an output schema present, the description needn't explain return values, and it still volunteers the isBuiltIn/reference-image behavior. For a single-param read tool this is essentially complete; only usage routing to list_entities is left implicit.

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?

One parameter at 100% schema description coverage, so the schema already documents entityId and its vg_enti_ prefix format. The description's 'by id' adds no syntax or format detail beyond the schema; baseline 3 applies.

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 (fetch) and resource (one entity by id), and adds scope detail: reference images included, built-in catalog entities returned with isBuiltIn true. It implicitly separates itself from list_entities by saying 'one entity', but never names the sibling explicitly.

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?

Usage is implied by 'fetch one entity by id' — the agent can infer this is the single-item lookup versus list_entities. There is no explicit when-to-use guidance, no prerequisites, and no exclusions (e.g., archived entities, permissions).

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