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

Annotations already establish the safe read profile (readOnlyHint=true, destructiveHint=false), so the bar is lower; the description adds real value on top: pagination via offset/limit, that the answer budget may shrink a page, and the non-obvious rule that the contentHash refers to the WHOLE source rather than the excerpt. That is substantial behavioral context beyond the annotations.

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 dense sentences, front-loaded with the default behavior and each clause carrying a distinct rule (view modes, required inputs, continuation/hash semantics, paging). Telegraphic style is efficient, though the run-on packing of rules slightly reduces scannability.

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 10-parameter, no-required-param tool with no output schema, the description does the heavy lifting on paging, view modes, continuation, and partial return shape (fragments[].full, fragments[].next). It leaves status/language behavior to the source card and never describes error or empty-result handling, but coverage is otherwise strong.

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?

With 80% schema coverage the baseline is 3, but the description adds cross-parameter semantics the schema cannot express: textOffset/textLimit require fragment, a continuation requires contentHash, and the hash scope warning. It also explains the textRange/fragments[].next continuation model, though it references a textRange that is not present in the schema.

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?

The description makes clear this retrieves official text sources, defaulting to short excerpts (view=summary) and offering full text (view=full), and it names law_search/law_rules as the origin of the StableId inputs. It does not, however, explicitly distinguish itself from sibling retrieval tools such as law_packages or law_editions, leaving the agent to infer the boundary.

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 specifies a key prerequisite ('Either package or fragment is required') and traces the StableId back to law_search/law_rules, which is genuine usage context. But it never states when to prefer this tool over the many sibling lookup tools, so usage is 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.