Get TRM (USD/COP official rate)

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

With no annotations, the description carries the full burden and does well: it discloses the holiday/weekend carry-over behavior, the series start date (1991-12-02), and the authoritative source. It omits anything about the response shape or rate limits, but for a read-only public rate lookup that is a minor gap.

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?

Four tight sentences, front-loaded with the core purpose, then behavior, then provenance. The source/dataset citation is marginally optional but inexpensive and supports trust, so nothing meaningfully wasteful.

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 one-optional-param read tool with no output schema, the description covers the key unknowns: default behavior, timezone, carry-over semantics, historical start, and units (COP per 1 USD). It never sketches the return payload, which is the only notable omission.

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% and there is a single optional parameter, so the baseline is 3. The description's 'omit the date for today's rate' and the Bogota-timezone note essentially restate what the schema already documents, adding no new parameter meaning.

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 ('Get Colombia's official TRM exchange rate (COP per 1 USD) for a date'), with units and scope made explicit. It does not explicitly name the sibling get_trm_range or convert_usd_cop, though 'for a date' (singular) implicitly contrasts with a range lookup.

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?

Gives clear operating context: 'Omit the date for today's rate' and the weekend/holiday carry-over rule tell the agent exactly how to call it and what to expect. It stops short of naming alternatives, e.g. when to prefer get_trm_range or convert_usd_cop instead.

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