Retrieve a URL and convert its HTML into clean, readable text, with an optional character limit for truncated results.
Fetch a URL and extract readable content (HTML → clean text).
Args: url: The URL to fetch max_chars: Max characters to return (default 20000, truncates if exceeded)
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | ||
| max_chars | No |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full disclosure burden. It does reveal two real behavioral traits: content is transformed to clean text, and output is truncated at max_chars (default 20000). It says nothing about network/error behavior, timeouts, redirects, or size/auth limits, so disclosure is partial.
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?
Very compact and front-loaded: the purpose sentence comes first, followed by a short Args block. The Args formatting is slightly redundant with the schema, but nothing 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?
For a two-parameter tool with an output schema, the description covers purpose and parameters adequately, so return values needn't be explained. It is still thin on when-to-use guidance relative to its siblings and on failure/limit behavior, leaving real gaps for an agent deciding between fetch, search, and research.
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%, but the description compensates by documenting both parameters: url is 'the URL to fetch' and max_chars is a character cap with a stated default and truncation semantics. This adds meaningful detail beyond the bare schema; only URL format requirements (scheme, absolute vs relative) are unstated.
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+resource (fetch a URL) and the transformation performed (HTML → clean text), so the agent knows exactly what comes back. It does not, however, differentiate itself from the siblings search and research, which are also retrieval tools.
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 indication of when to use fetch versus search or research, and no exclusions or prerequisites. The agent must infer that fetch is for a known URL while the siblings are for querying.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.