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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the description only needs to add context. It adds 'no key needed' and 'free preview' (no payment), which are useful. However, it omits what the preview returns (e.g., public metadata only) and includes confusing price/cost info about the underlying paid query without clarifying that preview itself is free.

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 a promotional pitch with redundant details ('FREE preview' repeated, price info for the paid query, sample questions) and key purpose info buried at the end. The opening is an imperative ('Call this now') rather than a clear technical description, making it neither concise nor well-front-loaded.

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 tool with two optional params and no output schema, the description still leaves out essential information: that it returns public metadata for any listing, that slug defaults to the routed listing, and that question is optional. It focuses entirely on one specific listing, which could mislead an agent into thinking the tool is only for Quanta Magazine.

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 baseline is 3. The description provides concrete sample questions and a specific slug (quantawatch), which adds real examples, but it does not explain parameter semantics beyond the schema, such as the optional nature of both parameters or that question is echoed back.

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 says 'FREE preview' and mentions 'Listing: quantawatch', which implies the tool previews a data listing, but it never states the general function ('preview public metadata of a listing'). The marketing tone ('Call this now') obscures the core purpose, and it does not clearly differentiate from siblings like data_session_query.

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 says 'No API key needed — call this now' but provides no explicit guidance on when to use this tool versus alternatives like data_session_query. It does not mention exclusions, prerequisites, or a decision framework for choosing a preview over a paid session.

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