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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the bar is lower. The description adds genuinely useful behavior beyond them: a response budget ("<= ~2KB") and an output-handling rule about source.verified that governs how the agent must phrase quoted text. It does not, however, describe failure behavior when no canonical law is matched.

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?

Short and front-loaded: the trigger condition leads, followed by budget, ordering, and output handling. The telegraphic style ("Budget: <= ~2KB") is dense but each clause carries distinct information, so there is little waste. Slightly compressed phrasing costs it a point.

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 structure need not be spelled out, and the description instead covers what the schema cannot: the size budget, the canonical-id purpose, and how to treat unverified sources. It is complete enough to call correctly, though it omits what happens on no-match or ambiguous references.

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 (reference, region) are already documented with examples in the schema. The description restates the reference concept ("citation, title, or partial reference") without adding format or matching semantics beyond what the schema provides, so the baseline 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 (resolve) and the exact output (one canonical law_id) for a specific input class (citation, title, or partial reference). It also names the siblings it precedes (get_law_context, read_law), so an agent can route correctly without opening any 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?

Opens with an explicit trigger condition ("WHEN you have a citation, title, or partial reference and need one canonical law_id") and gives an ordering rule versus two named alternatives ("Use this before get_law_context or read_law when the law is named"). When-to-use, when-not, and alternatives are all present.

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