Fetch a Japan Times author profile by canonical /author/// URL and return its name plus linked article cards; pagination is excluded because robots.txt disallows /page/ paths.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| data | Yes | The tool result payload (shape varies per tool; see each tool's docs resource). |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description goes further by disclosing the return payload (name + article cards) and the deliberate absence of pagination with its robots.txt rationale, which explains an otherwise surprising 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?
One dense sentence: purpose first, return contents second, the pagination/robots caveat last. No filler, and the most load-bearing information (input format, output shape) is 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?
An output schema exists so return values need no elaboration, yet the description still summarizes them. Input format, mutation profile via annotations, and the pagination limitation are all covered; nothing an agent needs to call this 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 coverage is 0% and the single url parameter carries no description, so the description must compensate. It does: it pins the required format to the canonical /author/<numeric-id>/<slug>/ path, telling the agent what a valid value looks like rather than just 'a string'.
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 names a specific verb (Fetch), the resource (Japan Times author profile), the exact input shape (canonical /author/<numeric-id>/<slug>/ URL), and what is returned (name plus linked article cards). An agent can distinguish it from japantimes_article/headlines/news without opening any 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?
Usage is implied: call it when you already hold a canonical author URL. It notes that pagination is intentionally excluded, but never names an alternative tool or states when-not-to-use it (e.g., for article bodies use japantimes_article). Context is present but routing guidance is thin.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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