safe_fetch_tool

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

With no annotations provided, the description effectively discloses behavioral traits: sanitization layer, detection of injections, failure modes, and different handling for trusted vs untrusted domains. This adds significant value beyond the schema.

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 relatively concise, front-loading the core purpose. The trusted/untrusted distinction could be more compact, but there is no fluff or redundancy.

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 single parameter and presence of an output schema, the description provides sufficient behavioral context (sanitization, failure, domain handling) for an agent to understand usage. It does not need to detail return values due to output schema.

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% for the single 'url' parameter. The description adds security context but does not enhance the parameter's semantics (format, constraints) beyond what the schema provides.

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 action ('Fetch URL') and its special behavior ('Layer 1 sanitization', 'fails if injection detected'). It distinguishes itself from siblings like quarantine_fetch_tool by specifying the security layer and failure conditions.

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 provides context on when to use by differentiating trusted and untrusted domains, and mentions failure/blocking behavior. However, it does not explicitly state when not to use or suggest alternatives like deep_quarantine_scan_tool for deeper scanning.

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