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

With no annotations, the description carries the burden of disclosure. It clearly explains the two distinct output structures depending on the presence or absence of the category parameter, which is valuable and not captured in the schema. It does not mention optional date behavior or limit caps, but those are already documented in the schema, so the additional context is meaningful.

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 sentences with a front-loaded, action-first opening. It efficiently presents the default behavior and the conditional alternative, with no redundant or irrelevant content.

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 tool has 5 parameters and no output schema, but the schema documents every parameter fully, and the description adds the key behavioral branching. It names the high-level return shapes but does not detail the LeaderboardEntry structure. This is adequate for correct invocation but not fully complete due to the absence of an output schema.

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 a baseline of 3 applies. The description adds semantic value by explicitly linking category values to the return type (highlights object vs LeaderboardEntry array), going beyond the schema's enum listing. Other parameters are left to the schema, but this added context for the most behavior-impacting parameter justifies a 4.

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 clearly identifies the tool as retrieving a ticker leaderboard for a given date, and distinguishes it from sibling tools like get_ticker_snapshot or get_ticker_history by focusing on leaderboard rankings. It also explicitly names the two possible response shapes, leaving no ambiguity about the tool's function.

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 implies usage when a ticker leaderboard is needed, but it does not explicitly state when to prefer this tool over alternatives or mention exclusions (e.g., only 'crypto' snapshot_type). The conditional category explanation helps the agent choose parameters, but no guidance is given on tool selection relative to siblings.

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