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

With no annotations provided, the description carries the full burden. It discloses the return fields (instrument name, type, price in USD/EUR, year), the indicative nature, and the meaning of a missing result. It does not mention rate limits or authentication, but for a read-only lookup tool this is adequate.

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 description is three sentences, each earning its place. It is front-loaded with the main action, followed by output details, then critical caveats. No filler or redundancy.

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?

Despite having no output schema, the description lists the return fields and adds crucial interpretative context (indicative vs. claimable, no-result meaning). This is sufficient for an agent to select and invoke the tool 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 coverage is 100%, so the baseline is 3. The description does not add extra meaning to the input parameters beyond what the schema already provides; it focuses on the output and usage context. No further credit is warranted.

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 opens with a specific verb and resource: 'Look up the carbon price(s) in a country (World Bank Carbon Pricing Dashboard)'. It clearly distinguishes itself by linking to a specific input on calculate_cbam_liability and explicitly stating it is not the Article 9 claimable value, setting it apart from potential sibling lookups.

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?

Explicit when-to-use guidance is provided: 'as an INDICATIVE starting figure for the carbon_price_paid_eur_per_tonne input on calculate_cbam_liability'. It also gives a when-not: 'Not the claimable Article 9 value', and explains that no result means no implemented carbon price, which is vital context for interpreting the tool's output.

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