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

With no annotations, the description carries the full behavioral burden and discloses useful traits: HTTP GET, price via x402, docs URL, and output shape referenced as 'same shape as /v1/movers.' It also explains ranking behavior (absolute probability change over the chosen window) and volume surge ratios. It stops short of rate limits, pagination, or full return-field details, but adds substantial context for an unannotated API tool.

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 front-loaded with the core purpose and then adds useful context about ranking and output shape. The bracketed HTTP/pricing metadata is compact and valuable. The second sentence leans slightly marketing-oriented ('fastest way'), but overall it is efficient and well structured.

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 data query tool with no output schema and no annotations, the description provides a docs link and a reference to the shared output shape, which helps. However, the required limit parameter is undocumented in both schema and description, and the relationship between the pre-filtered US politics scope and the category parameter is unclear. It is adequate but leaves meaningful invocation questions unresolved.

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 only 25%, so the description should compensate but largely does not. It mentions window values (1h/6h/24h) that are already in the enum, and 'pre-filtered to US politics markets' hints at the category parameter, but the required limit parameter is never explained and category semantics remain ambiguous given the pre-filter claim. The min_liquidity parameter's meaning comes only from the schema.

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 and scope: US politics probability moves over 1h/6h/24h windows. It distinguishes itself from the generic probability_movers tool by saying it is 'pre-filtered to US politics markets,' and from politics-world by specifying US. An agent can identify exactly what this tool does without opening the schema.

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 through 'the fastest way to see where news is landing in US politics,' which suggests a timely news-monitoring use case. However, it never states when to use this tool versus siblings like probability_movers, probability_movers_politics-world, or probability_board_politics-us. No explicit alternatives or exclusions are given.

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