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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds valuable context: 'Keyless' (no authentication) and the specific 3-hour resolution up to 72 hours. The description also lists the exact data fields, providing behavioral expectations beyond the annotations. No contradiction.

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?

Single sentence that front-loads the tool's purpose ('General weather forecast from 7Timer! CIVIL') and efficiently lists the data fields and resolution. No filler or redundancy.

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 weather forecast tool with no output schema, the description sufficiently enumerates the returned data types and time resolution. It lacks units or error conditions, but the annotations cover safety, making this adequate for selection.

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?

The schema already describes all three parameters (latitude, longitude, hours) with 100% coverage, so the baseline is 3. The description reinforces the hours resolution ('3-hour resolution out to 72 hours') but does not add additional parameter semantics beyond 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?

The description clearly states the tool provides a 'General weather forecast from 7Timer! CIVIL' with specific data fields (temperature, humidity, condition code, cloud cover, wind, precipitation). This is distinct from sibling tools like stargazing_forecast by explicitly focusing on weather conditions.

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?

No explicit alternative guidance is given. The phrase 'General weather forecast' implies this is the default weather tool, but it does not mention when to prefer sibling tools like stargazing_forecast or ai_visibility_check. Usage context is implied rather than stated.

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