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

Annotations already cover the safety profile (read-only, idempotent, non-destructive, open-world), so the description's job is to add operational context — and it does: it warns the text is long, points to max_chars, and states that the response reports truncation. It doesn't mention error behavior for invalid citations, but the added value is real.

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 sentences, front-loaded with the action and accepted inputs, then the return contents, then the practical constraint. No filler or repetition.

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?

There is no output schema, but the description compensates by enumerating what comes back (judgment text plus case name, court, date, citation) and noting the truncation indicator. Nothing an agent needs to call this correctly is missing.

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%, so both parameters are already documented with examples in the schema; baseline is 3. The description adds the practical rationale that text is long and max_chars bounds it, but no format details beyond what the schema and its examples already give.

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 — fetching the FULL TEXT of a UK judgment — and specifies the two accepted input forms (neutral citation, Find Case Law identifier). An agent can tell it apart from search_uk_caselaw because this is a direct lookup rather than a search.

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?

Gives clear triggering context: use it when a quoted passage or cited authority needs to be verified against what the court actually wrote, and it explains that max_chars should be used to bound long output. It never explicitly names search_uk_caselaw as the alternative for finding a citation, which keeps it just below 5.

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