web_read

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

With no annotations provided, the description carries the full burden and does so admirably. It discloses the asynchronous fallback to a browser renderer for SPAs, the optional dependency (`engawa-mcp[browser]`), the stateless nature (no login/history), and the limitation with login-walled sites. This is exactly the kind of behavioral context that helps an agent set expectations.

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?

Despite its length, the description is well-structured with clear labels (Boundaries, Args, Returns) and front-loaded with the core purpose. Every sentence adds value—the implementation detail of static vs. browser fallback is relevant for performance expectations, and the 'note' field disclosure avoids surprising the agent.

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?

Given the absence of an output schema, the description specifies the exact return shape ({ok, title, content, total_length, links (≤10), note}) and clarifies edge-case behavior (e.g., pagination, link following). This makes the tool fully usable without external documentation, which is especially valuable for a tool with no annotations.

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?

Input schema has 0% description coverage, so the description compensates fully. The Args section explains `url` (full URL with scheme), `offset` (character offset for paging), and `length` (max characters, default 3000). It also explains the behavior of the return fields, particularly `total_length` for pagination.

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 opens with a clear verb and resource: 'Read any web page: give a URL, get title + clean article text + links.' It clearly differentiates the tool from siblings by focusing on generic web fetching, which is distinct from the more niche sibling tools like rss_read and shelf. The output contract (title, content, links) is explicit.

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?

Provides explicit guidance on when to use: 'No login state, no history,' 'To "click" a link, call web_read again,' and explicitly excludes login-walled platforms like x.com. It also explains the two execution lanes (static vs. SPA fallback) and paging, giving the agent clear context about boundaries and alternatives.

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