get_sources

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

With no annotations provided, the description carries the full burden. It discloses that the tool returns a 'full source list' from 'cached sources', implying a read-only operation. It does not discuss potential failure modes or session validity, but for a simple retrieval tool it provides sufficient behavioral context about what the agent can expect.

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 spread across three sentences with notable redundancy: 'session_id returned by web_search' appears in all three, and the first sentence is verbose and contains a typo ('the this tool'). It could be condensed to one or two sentences without losing meaning.

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 one-parameter tool with an output schema, the description adequately covers what the tool does, when to use it, and how to provide input. It does not describe error scenarios, but those are not critical for basic usage. The sibling tools are distinct enough that confusion is unlikely.

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 coverage is 100%, so the baseline is 3. The description adds value beyond the schema by explicitly stating the session_id's provenance ('returned by web_search') and its purpose ('to get the full source list'). This reinforces the schema description and helps the agent understand how to obtain and use the parameter.

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 'Retrieve all cached sources for a previous web_search call', a specific verb+resource. It distinguishes itself from sibling tools by explicitly linking to web_search and mentioning 'session_id returned by web_search'. The purpose is unequivocal and not a tautology.

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 first sentence provides an explicit trigger: 'When you feel confused or curious about the search response content, use the session_id returned by web_search to invoke this tool'. This tells the agent exactly when to use the tool, and the repeated reference to 'previous web_search call' clarifies that it is not for initiating new searches, distinguishing it from web_search.

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