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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds the useful 'structure only, no content' scoping of what comes back, but says nothing about the shape of that structure (fields vs. edges) or what happens when name_hash matches nothing.

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 lookup key and scope, with zero filler. Every clause carries information the agent needs to invoke the call correctly.

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 single-key read tool with full schema coverage and rich annotations, the description covers key, scope and the read-only nature adequately; no output schema exists, so return values need not be described. The only residual gap is that 'STRUCTURE' is never defined (which fields or relations are returned), which an agent may want in order to use the result.

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 100% and the description's parenthetical gloss on name_hash ('SHA-256 of the normalised name') essentially restates the schema text verbatim. The node_id compatibility caveat is likewise documented in the schema, so the description adds no meaning beyond structured fields.

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 ('Get'), a specific resource ('one entity's STRUCTURE'), and the exact lookup key ('by name_hash (SHA-256 of the normalised name)'). The trailing 'No content.' explicitly differentiates it from the sibling get_entity_content, so an agent can choose correctly 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?

The 'No content' constraint clearly scopes when this tool applies versus get_entity_content, and the name_hash requirement sets the precondition for a meaningful lookup. It stops short of naming the alternative tool explicitly, so the routing is strongly implied rather than spelled out.

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