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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds genuinely useful behavior: an empty container text does not mean the law is absent, and metadata.structure carries parent/child addresses. Missing rate/timeout or error behavior keeps it short of 5.

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?

Four sentences, front-loaded with purpose and return scope before the traversal and id-handling caveats. Nothing is padding, though the sentences are dense and the traversal note could be trimmed slightly.

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?

An output schema exists, so return-value documentation is not required, yet the description still orients the agent on structure and empty-container semantics. Traversal guidance and input provenance complete the picture for a single-parameter read tool.

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% and the schema already calls the id opaque and search-returned, so baseline is 3. The description goes further by warning against editing the id, adding a usage constraint the schema does not encode.

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 ('Retrieve one search result by its opaque id') and enumerates the returned content (provision text, canonical URL, authority status, provenance), which distinguishes it from the sibling `search` and from `lookup_provision`. An agent can tell what this tool does without opening the 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?

It names the alternative route ('Use child apiHref links or lookup_provision with sourceLang to traverse') and constrains input provenance ('ids returned by search without editing them'). That gives clear context and a fallback path, though it never states an explicit when-not-to-use condition for this tool versus lookup_provision.

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