Carpe Diem prices

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds genuine value by saying prices are 'live' and by defining the price fields (inputPrice/outputPrice are post-multiplier, inputBase/outputBase are Venice list prices) and that media pricing is a fixed per-call USD figure. That field semantics is useful context, though it edges into return-value territory rather than behavior of the call itself.

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 short, front-loaded fragments with no filler: what it returns, how token prices are expressed, how media prices are expressed, and how to filter. The telegraphic style ('Free.') is efficient for an agent reader, though the fragment structure makes the field-semantics sentence dense on first read.

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?

With no output schema, the description carries the burden of explaining return values and does so for the price fields, which is the most important missing piece. The remaining gaps are the undocumented sort enum and the shape of a media row. For a four-parameter read-only lookup these are minor, and the annotation coverage plus field definitions make it callable without guessing.

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 75%: kind and limit carry descriptions, model is covered, and only sort is undocumented in both places. The description repeats the model-substring filter and adds no syntax or default details for sort, so it does not compensate for the one gap. Baseline 3 is appropriate given the schema does most of the work.

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 resource (live Carpe prices) and immediately splits it into two priced categories, token models vs media, which tells an agent exactly what data comes back. It does not name the nearest siblings (carpe_model_details, carpe_quote, carpe_markets), so differentiation is left implicit, but the 'prices' framing is clear enough to distinguish it from a catalog or quote tool.

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?

There is no explicit when-to-use guidance and no mention of alternatives such as carpe_model_details for a single model or carpe_quote for a cost estimate. The only procedural hint is 'Filter by model substring', which is a parameter behavior rather than a usage rule. An agent must infer the routing decision from the tool name alone.

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