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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds real behavioral context beyond them: single-record scope, the absence of legal opinion/applicability output, and the JSON-for-pipelines option. It does not mention auth or rate-limit behavior, so not a full 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?

Front-loaded with a labeled Purpose/Guidelines/Limits/Ex structure that is easy to scan and contains no filler prose. The three closing examples are slightly redundant (name='CBAM' and name='2023/956' illustrate the same idea), keeping it short of a 5.

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 names the fields returned. Combined with the id/name alternative explanation, the query_policies dependency, and the exclusions, an agent has everything needed to call this correctly.

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 the schema already documents id, name, language, and response_format. The description reinforces with concrete value formats (rcb-pol-001, 'CBAM', '2023/956') and ties id to its source query_policies, but adds little syntax the schema lacks. 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+resource ('fetch one regulation record in full') and enumerates the returned fields (issuing body, policy type, scope, impact, deadline, source link, AI summary). It clearly distinguishes itself from the list-oriented sibling query_policies by emphasizing 'one record per call'.

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?

Explicitly routes the agent: use the id from query_policies (rcb-pol-xxx) or a name keyword, and 'run query_policies first when the id is unknown.' It also states the exclusions (no legal opinion, no applicability assessment) and the response_format='json' path for agent pipelines, so when-to-use and when-not are both covered.

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