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

With no annotations at all, the description carries the full burden, but it does disclose genuinely useful behavior: the rate is the 'latest BoC daily average', telling the agent the data source and that quotes are daily-averaged rather than live. It says nothing about auth requirements despite an access_token parameter, nor about error behavior for unsupported currencies.

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?

A single sentence with no waste, front-loading the verb and the CAD/BoC constraint. The 'PRO.' tag is cryptic but compact; the 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 4-parameter tool with no annotations and no output schema, the description should say what comes back (converted amount and/or rate) and how access_token affects the call. Neither is covered, leaving the agent to guess at the response shape and auth path.

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 only 25% (just access_token), so the description must compensate. It does clarify the amount and that one leg must be CAD, but it never explains that 'from'/'to' are currency codes, what format they take, or whether CAD may appear in either position.

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 (convert), the resource (an amount between CAD and another currency), and the rate source (BoC daily average). The CAD/BoC scoping implicitly separates it from the ECB and 'global_fx' siblings, though no sibling is named 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?

No explicit when-to-use or when-not-to-use guidance is given; the CAD + BoC scope only implies that this is the domestic option versus global_fx_convert or ecb_reference_rates. The 'PRO' prefix hints at a paid tier but never states prerequisites for choosing this tool.

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