Weather

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

Annotations already declare read-only, idempotent, open-world, non-destructive, so the safety profile is covered. The description adds what annotations cannot: pricing via x402 ($0.01 USDC on Base), no-charge on empty results, no account/API key needed, and which endpoints are free — genuinely decision-relevant 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?

Front-loaded with purpose first, then the parameter, then the return content and pricing constraints. The trailing 'Free tools: health and tools/list' line is slightly tangential, but everything else earns its place for an agent deciding whether to spend money.

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?

Covers purpose, input format, coverage limits, cost model, and free alternatives; the return fields are further backed by an output schema. Nothing an agent needs to decide or invoke correctly is missing.

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 single state parameter is already fully documented including the CA/NY example. The description repeats rather than extends the schema, which is the expected baseline.

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 verb and resource ('Get active weather alerts for a US state') and names the exact data source (National Weather Service). An agent can tell it apart from get-forecast without opening either 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?

Gives clear context (active alerts only, US locations only) and the input convention (two-letter state code). It does not explicitly name get-forecast as the alternative for forecast data, so the sibling routing is only implied.

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

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

Annotations only declare the read-only/idempotent profile; the description goes well beyond by disclosing the x402 payment flow ($0.01 USDC on Base), no API key/account requirement, and the crucial 'nothing is charged when the request returns no data' clause. It also states exactly what comes back (period name, temperature, wind speed/direction, plain-language forecast), which is behavior an agent needs before spending money.

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?

Purpose is front-loaded in the first sentence, then output, then coverage limits, then pricing. The pricing sentence is dense and packs several facts at once, and the trailing 'Free tools' note feels slightly bolted on, but no sentence is wasted.

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?

An output schema exists, so return values need not be spelled out, yet the description still summarizes the forecast fields, coverage limits, and the cost/failure-charging semantics. For a paid, open-world tool this is exactly the information an agent needs to decide whether to call it.

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 coverage is 100% and both parameters already carry descriptions, so the schema does the heavy lifting. The description only restates 'give latitude and longitude' and adds the framing of a map point, which is marginal value over 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 verb and resource ('Get the weather forecast for a point on the map') and scopes it geographically ('US locations only'). It is trivially distinguishable from siblings get-alerts (alerts, not forecasts) and health (mentioned explicitly as a free tool).

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?

Gives clear conditions for use: supply lat/long, US-only coverage, and it names the free tools (health, tools/list) so an agent can route pre-flight checks away from this paid tool. It does not explicitly contrast with get-alerts, but the resource difference is self-evident.

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

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=true, so safety and repeatability are covered by structured data. The description adds one genuinely new trait — that the call has no cost — but says nothing about latency, auth requirements, or what distinguishes a healthy from a degraded result.

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?

Two short sentences, zero filler, with the core function front-loaded and the cost note as a secondary qualifier. Nothing is wasted and nothing important is buried.

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?

With no parameters, no nested objects, and rich annotations, the only remaining gap is return shape: there is no output schema and the description does not say whether the result is a boolean, a status string, or a version payload. Minor, but it means an agent cannot predict the response format.

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 tool takes zero parameters, so there is no parameter semantics for the description to explain. Baseline for a zero-parameter tool applies, and the description correctly avoids inventing parameter commentary.

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 verb and resource: 'Check that the service is up.' That is unambiguously a liveness/health probe and cannot be confused with the data-retrieval siblings get-alerts and get-forecast. It stops short of naming the service or endpoint being probed, but the intent is clear.

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?

'Costs nothing' hints that it can be called freely, which weakly implies a pre-flight or connectivity-validation use case. However, it never says when to call it versus the siblings, nor whether it validates auth or downstream dependencies versus simple process liveness. Usage 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.