get_source

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

With no annotations, the description carries the burden of behavioral disclosure. It explains the field-subsetting behavior and the 'cheaper' nature, which is useful, but it does not mention error cases, authentication needs, or explicit read-only guarantees. The term 'Get' implies read-only, but that is not stated.

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 two sentences: the first states the core purpose, the second explains a smart usage hint. It is concise, front-loaded, and every sentence adds value without 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?

For a single-resource getter, the description covers the main purpose, the optional field filtering, and a performance consideration. Since an output schema exists, return values need no further explanation. It is missing some details about parameter roles, but overall it is complete enough for straightforward 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. It explains the 'fields' parameter in detail (comma-separated top-level keys, subset of payload, cost efficiency), but does not clarify 'source_id' or 'account_id', though their purpose is implied by their names. The compensation is partial.

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 opens with 'Get full details for a specific source,' which clearly identifies a single-resource retrieval operation. The verb 'get' and resource 'source' distinguish it from sibling tools like 'list_sources' and other resource-specific getters.

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 clear usage context by explaining when to use the 'fields' parameter ('when checking several sources in a row') and emphasizes the cost benefit. It does not explicitly mention alternatives or when not to use the tool, but the purpose is evident from the resource-specific naming.

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