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

Annotations already establish readOnly, idempotent, openWorld and non-destructive behavior, so the description's main added value is the operational cost disclosure ('cost: 3 credits'), which helps an agent budget calls. It still omits whether authorization is required, whether results are fuzzy-matched or exact, and any rate limits.

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 compact sentences, front-loaded with the action and data source, and the cost note is parenthetical rather than buried. Minor redundancy in repeating 'UK' three times and the trailing audience clause could be trimmed without loss.

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 previews the returned fields (regime, measures, designation date) and the entity types covered, which is enough to call it correctly. It stops short of describing result ordering, how matches are scored, or what an empty result means for a six-parameter screening tool.

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 all six parameters are already documented in the schema; baseline 3 applies. The description reinforces the type dimension by naming 'person, company or ship', but says nothing about dob, country, limit, or how minScore affects matching, so it adds little beyond 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?

States a specific verb and resource ('Search the UK Sanctions List') plus what the results carry (regime, measures such as asset freeze or travel ban, designation date). The 'UK' qualifier and FCDO/OFSI attribution implicitly distinguish it from eu_sanctions_check, un_sanctions_check and ofac_check, but it never names those siblings explicitly.

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?

The clause 'For UK firms meeting their UK sanctions obligations' gives a usage context, so the agent knows this is a compliance-screening call. However, it offers no when-not guidance and no routing among the crowded sibling set (sanctions_screen, sanctions_check_person/company/ship, eu/un/ofac checks), leaving selection to inference.

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