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

Beyond the readOnlyHint and openWorldHint annotations, the description discloses important behavior: rows missing open_mid_probability_utc or probability_delta_today are dropped, predictionRankIndex is required, and the tool is public research data with no account access or trading capabilities. This gives the agent concrete expectations beyond safety flags.

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 compact and front-loaded with the core '[Read]' purpose and ranking metric. Every sentence contributes distinct value: filter semantics, row-dropping behavior, prerequisite index, read-only nature, and disclaimer. No filler or redundant restatement of the schema.

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 read-only ranking tool with optional parameters and an output schema, the description is complete: it states the prerequisite index, data filtering behavior, scope of access, and the ranking basis. The output schema covers return values, so no additional output explanation is needed.

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 100%, so the structured schema already documents all five parameters. The description adds only a reference that filters match volume_delta ranking and a UTC date context, which is useful but not necessary to disambiguate the parameters.

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 returning a daily ranking sorted by probability rise, with optional venue/category/status filters. It distinguishes itself from the sibling volume_delta_ranking by naming the sorting metric and explicitly referencing that sibling for filter semantics.

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 by stating the ranking is by probability rise and noting that optional filters are the same as volume_delta ranking. However, it does not explicitly state when to choose this tool over alternatives or provide exclusions, leaving the agent to infer when it is the appropriate choice.

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