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

Annotations already cover the safety profile (readOnlyHint=true, idempotentHint=true, destructiveHint=false). The description adds 'no key needed' and 'free', which is useful, but it also introduces misleading 'sample questions' that imply the tool will answer weather-alert queries, whereas the schema says the question is merely 'echoed back' and the result is 'public metadata only'. This confuses rather than clarifies behavior.

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 marketing-heavy and repetitive: 'FREE preview — no key, no payment' effectively appears twice, and the sentence about the specific listing, pricing, and sample questions is not directly about tool mechanics. It is longer than needed and not tightly structured for an agent to parse quickly.

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?

There is no output schema, so the description should help an agent understand what a call returns; it does not. The key fact that this returns only public metadata and echoes the question appears only in the input-schema description, not the tool description. The irrelevant pricing and weather-alert details add confusion instead of completeness.

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 schema already documents both parameters clearly. The description's sample questions loosely map to the 'question' parameter, but they imply a richer behavior than the schema supports, and it adds nothing about the 'slug' parameter. Baseline 3 is appropriate.

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 does indicate this is a 'FREE preview' of a listing, so an agent can infer a preview action. However, it is muddled by listing-specific marketing copy ('Listing: usweather...') and sample questions that belong to that listing, not clearly to the tool itself. It never explicitly states that the tool returns public metadata only.

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 strongly urges immediate use ('No API key needed — call this now') and emphasizes that it is free, which gives a clear trigger condition. But it gives no when-not-to-use guidance, no comparison with paid alternatives like data_session_query, and no explanation of when this tool is preferable to the data_session_* siblings.

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