reference_read_source

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

With no annotations, the description must disclose behavior itself. It states the tool is SSRF-guarded and capped, and that a reason is required, which gives meaningful safety and size constraints. However, it does not define the cap size, error behavior, or output format beyond 'full source', leaving some ambiguity.

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 a single, front-loaded sentence that packs the action, resource, constraints, and usage guidance with no wasted words. Every phrase adds value.

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 simple 2-parameter tool with no output schema, the description covers purpose, when to use it, and key behavioral constraints. It doesn't explain exact return structure or error cases, but the core information needed for correct selection and invocation is present. Sibling tools are named for context.

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?

The schema covers the 'reason' parameter with a description, but the 'url' parameter has no schema description. The tool description adds that the URL is SSRF-guarded and that reason is required, partially compensating. Yet it doesn't clarify acceptable URL formats or what counts as a valid target, leaving the 50% coverage gap only partially filled.

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 fetches and returns the FULL source of a page (HTML/text), using a specific verb and resource. It explicitly contrasts with siblings (inspect/excerpt) by calling itself an 'escape hatch', distinguishing its role and scope.

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?

It provides clear usage context: use when inspect/excerpt are not enough, and requires a reason. This tells the agent when to select this tool over alternatives like reference_inspect and reference_excerpt, and what prerequisite must be satisfied.

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