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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds real value beyond them: it discloses the AND-matching rule ('contain all the given words'), the return shape (lines with their chapter), and the ordering convention (a regulation's own heading first) — all critical given there is no output schema.

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 sentences, each doing distinct work — the first routes usage, the second explains the return format. Front-loaded and free of filler, though 'UDCPR' is repeated where a pronoun would do.

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 no output schema, the description usefully explains what comes back (matching lines, chapter, heading ordering). It stops short of noting result limits, pagination, or case-sensitivity, which an agent would want before invoking.

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 single `words` parameter is already documented as requiring all words to appear on the line. The description restates the same AND semantics and adds the example 'refuge areas', but no new syntax or formatting guidance beyond the schema, so the baseline of 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 and resource: search UDCPR text for lines containing given words, scoped to a domain (regulations like refuge areas). It is clearly not a generic search, but it never names the sibling `search` or `clause` to disambiguate, so the distinction must be inferred.

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?

Provides an explicit usage trigger: 'Use this when someone asks where UDCPR deals with a topic.' That is clear context, but there is no when-not condition and no routing to alternatives such as the sibling `search` or `clause`.

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