fetch-save

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes key behavioral traits: that the tool performs a download operation, permanently stores data to the filesystem, grants internet access capability, and fetches up-to-date information. However, it doesn't mention potential limitations like file size constraints, network timeouts, or error handling scenarios.

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 appropriately front-loaded with the core functionality, but contains some redundant phrasing and historical context about internet access that could be more concise. The third paragraph about previously lacking internet access adds context but could be integrated more efficiently into the usage guidelines.

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 tool with 2 parameters, 100% schema coverage, and no annotations or output schema, the description provides good contextual completeness. It explains the tool's purpose, usage context, behavioral characteristics, and internet access capability. The main gap is the lack of information about return values or error conditions, which would be helpful given there's no 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?

The input schema has 100% description coverage, providing clear documentation for both parameters. The description adds some context by mentioning 'downloading and storing web content' and 'local file for storage and future use,' but doesn't provide additional semantic details beyond what's already in the schema descriptions. This meets the baseline expectation when schema coverage is complete.

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 ('fetches', 'saves', 'downloading', 'storing') and resources ('URL', 'web content', 'local file', 'filesystem'). It explicitly distinguishes this from a hypothetical 'regular fetch tool' that only displays content, establishing clear differentiation even without actual sibling 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?

The description provides explicit guidance on when to use this tool: 'When you need to both access online content AND save it locally for later use or processing, THIS is the appropriate tool to use.' It also clearly contrasts with an alternative ('regular fetch tool which only displays content') and specifies the tool's internet access capability that overrides previous limitations.

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