fetch-guard

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

With no annotations provided, the description carries full burden and does well by disclosing key behavioral traits: it performs web fetching with timeout control, content extraction with word capping, JavaScript rendering options, link extraction modes, and security features like injection scanning and sanitization. It doesn't cover rate limits or auth needs, but provides substantial operational context.

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 description is well-structured with a purpose statement followed by Args and Returns sections. It's appropriately sized for a 6-parameter tool, though slightly verbose in the Returns section. Every sentence adds value, but could be more front-loaded with the core purpose.

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 6 parameters with 0% schema coverage and no output schema, the description provides strong contextual completeness. It explains all parameters, outlines the return structure, and covers behavioral aspects like security scanning. Minor gaps include lack of error handling details or example outputs, but it's largely sufficient for agent use.

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 0%, so the description must compensate fully. It does so by explaining all 6 parameters with clear semantics: url (URL to fetch), timeout (request timeout in seconds), max_words (optional word cap), strict (error on high-risk injection), js (use Playwright for JavaScript), and links (extraction mode with options). This adds significant value beyond the bare 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?

The description clearly states the tool's purpose with specific verbs ('fetch a URL', 'return clean, LLM-ready markdown') and resources (URL content). It distinguishes itself by mentioning unique features like prompt injection scanning and markdown conversion, even without sibling tools for comparison.

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?

The description implies usage context through parameter explanations (e.g., 'js' for JavaScript-rendered pages, 'strict' for high-risk injection handling), but lacks explicit guidance on when to use this tool versus alternatives or prerequisites. No sibling tools exist, so no comparison is needed.

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