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

Annotations already declare the tool read-only and non-destructive. The description adds meaningful behavioral context beyond that: sources remain separate, results are limited to stored data, and there is no consolidated best-price or live representation. This helps set expectations about what the tool returns.

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 two short sentences with no filler. The core operation and scope are front-loaded, and the behavioral caveat about separate sources and no live/best-price claim is stated economically.

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 is adequate for a moderately complex list tool: it states inputs at a high level and the kind of data returned. However, with no output schema, it leaves gaps around response shape, pagination behavior, and what exactly a 'source' entry looks like.

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 description coverage is 0%, so the description must compensate. It partially does by clarifying that asset_id is an exact asset and date_from/date_to form a UTC window, but it does not explain limit or cursor, or describe how pagination and source/interval filtering 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?

The description uses a specific verb and resource: 'Find stored price sources and available candle intervals'. It also scopes the operation to 'an exact asset and UTC window' and explicitly differentiates the tool by stating it makes 'no best-price or live claim', separating it from live and aggregated price tools.

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?

The description clearly indicates when to use this tool: when you need stored price sources and available candle intervals for a precise asset and UTC range. It also communicates exclusions by saying the tool makes no live or best-price claim, though it does not name sibling alternatives explicitly.

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