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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds the 'newest decision first' ordering and the optional filters, which are useful. However, it doesn't disclose details like whether results are limited to a certain time window, how 'recent' is defined, or pagination behavior beyond the limit parameter.

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 with zero waste. The core purpose and ordering are front-loaded, the optional filters are listed compactly, and the use-case examples are embedded naturally. Every sentence earns its place.

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?

For a read-only list tool with 100% schema coverage and no output schema, the description is largely complete. It explains what the tool returns, the ordering, the optional filters, and the intended use cases. The only minor gap is that 'recent' is not precisely defined (e.g., default time window), but the since parameter and examples mitigate this.

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 all six parameters. The description adds context by naming the filter dimensions (member state, condition, sponsor, phase) that map to country, condition, sponsor, and phase parameters, but it doesn't add syntax or format details beyond the schema. Baseline 3 is appropriate.

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?

The description clearly states the tool lists clinical trials most recently authorised in the EU/EEA, newest first, from a specific system (CTIS). It names the resource (clinical trials authorisations), the action (list/recent), and the ordering (newest decision first). It also distinguishes itself from the sibling ctis_search_trials by focusing on recency rather than general 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?

The description gives concrete use cases: 'what did the EU authorise this month' and 'what sponsors are starting in Europe now.' It also explains optional narrowing by member state, condition, sponsor, or phase. It doesn't explicitly say when NOT to use it versus ctis_search_trials, but the recency framing and examples make the intended context clear.

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