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

There are no annotations, and the description does not disclose behavioral details: no mention of return format, update frequency, data source, or read-only nature. It is a noun phrase that does not even explicitly state that invoking the tool returns a value.

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?

The single-sentence description is extremely concise and front-loaded, with no filler or redundant phrases. Every word contributes to identifying the data series, which is appropriate for a tool with no inputs.

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?

The description names the exact data point but lacks context about the returned value (e.g., current value vs. time series, units, timestamp, or data source). With no output schema, this leaves the agent to infer the output structure, though the tool's low complexity makes it minimally adequate.

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?

This tool has zero parameters, so the schema provides no parameter information and the baseline is 4. The description adds semantic meaning by specifying the exact series (Euro Area 10Y AAA government bond yield), which is sufficient for a parameterless call.

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 identifies the resource precisely: 'Euro Area 10Y AAA government bond yield benchmark,' with region, maturity, and rating qualifiers. This differentiates it from broader siblings like ecb_rates or yield_curve, though it lacks an explicit action verb like 'retrieves' or 'returns.'

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?

No guidance is given on when to use this tool instead of related tools such as ecb_rates, ecb_dashboard, or yield_curve_v1-3. The description states only what the benchmark is, not when it should be selected.

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