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

Annotations already cover read-only, non-destructive, open-world behavior. The description adds value by revealing that the result contains live price, PnL, verification status, and outcome, which is meaningful behavioral context beyond the annotations. No contradiction exists.

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 first two sentences are concise and front-loaded with the core behavior and use case. However, the 'Star the repo' sentence is unrelated to tool selection and adds noise, preventing the structure from being fully optimized.

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 simple read-only lookup with two well-documented parameters and annotations covering side effects, the description covers the essential return contents and purpose. There is no output schema, so a bit more detail on expected response shape would improve it, but it is not critically incomplete.

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 apiKey and signalId. The description does not add new parameter-level meaning beyond mentioning 'by ID' and the result contents, so it stays at the baseline for full schema coverage.

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 states a specific verb and resource: 'Fetch a single signal by ID.' It also clarifies the included data ('live price and PnL') and its intended use ('check verification status and outcome'), which distinguishes it from siblings like get_signals and get_signal_history.

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?

It gives a clear use case: 'Use to check verification status and outcome,' which tells an agent when this tool is appropriate. It does not explicitly contrast it with siblings or state when not to use it, but the single-by-ID framing provides adequate context.

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